Journal of Occupational Health Psychology                                           Copyright 1998 by the Educational Publ...
SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE                                        323(d) physical demands and (e) job inse...
324                                            KARASEK El" AL.Table 1Scales and Numbers of Questions in the Full Recommend...
Decision          l                                 Ltit:dAichite_Lc                                                 t    ...
326                                               KARASEK ET AL.developments in production processes, thus making it      ...
SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE                                        327approach uses the workers occupation ...
328                                             KARASEK ET AL.(Karasek et al., 1981; Karasek, Schwartz, & Pieper,        s...
SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE                                        329pressures are too much for me" are re...
330                                            KARASEK ET AL.very similar to the JCQ scales have been published         up...
SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE                                       331JCQ Breadth of Use and Scale Consisten...
332                                             KARASEK ET AL.recommended version since 1985 (and provisionally           ...
SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE                                       333forms of nonmarket productive output t...
334                                                 KARASEK ET AL.populations themselves are not the focus. However,      ...
SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE                                                      335and random samples of 4...
336                                                KARASEK ET AL.Cronbach alpha reliable scale variance (this represents  ...
SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE                    337                 ~   ~           I     I ~               ...
338                                                KARASEK ET AL.Table 4Cronbach s Alpha Reliability Coefficients of the J...
SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE                                        339strain" combination. The correlation ...
340              KARASEK       ET AL.      x_.                           @                                            I   ...
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  1. 1. Journal of Occupational Health Psychology Copyright 1998 by the Educational Publishing Foundation1998, Vol. 3, No. 4, 322-355 1076-8998/98/$3.00 The Job Content Questionnaire (JCQ): An Instrument for Internationally Comparative Assessments of Psychosocial Job Characteristics Robert Karasek Chantal Brisson University of Massachusetts Lowell Laval University Norito Kawakami Irene Houtman and Paulien Bongers Gifu University National Institute for Work and Health Benjamin Amick New England Medical Center Part I discusses the Job Content Questionnaire (JCQ), designed to measure scales assessing psychological demands, decision latitude, social support, physical demands, and job insecurity. Part II describes the reliability of the JCQ scales in a cross-national context using 10,288 men and 6,313 women from 6 studies conducted in 4 countries. Substantial similarity in means, standard deviations, and correlations among the scales, and in correlations between scales and demographic variables, is found for both men and women in all studies. Reliability is good for most scales. Results suggest that psychological job characteristics are more similar across national boundaries than across occupations. This article consists of three parts. Part I introduces Part II reports the cross-national validity, for menthe Job Content Questionnaire (JCQ) as a tool for and women, of the JCQ scales in six broadlypsychosocial job assessment. First, a description of representative populations from four advanced indus-scales and their underlying theoretical concepts is trial societies: the United States, Canada, thepresented. This is followed by a discussion of Netherlands, and Japan. JCQ scale means, standardempirical issues in the development of the question- deviations, reliabilities, and correlations are com-naire and its validity. Part I concludes with a pared. Part III reviews comparison of the intercountrydiscussion of measurement issues, administrative and interoccupation differences in the scales, dis-issues, and future challenges. cusses specific scales issues, and discusses the implications of the study for interpretation of psychosocial job assessment questionnaires. Robert Karasek, Department of Work Environment,University of Massachusetts Lowell; Chantal Brisson, PART IDepartment of Preventive and Social Medicine, LavalUniversity, Quebec City, Quebec, Canada; Norito Kawakami,School of Medicine, Department of Public Health, Gifu The Job Content Questionnaire (JCQ):University, Gifu, Japan; Irene Houtman and PanlienBongers, National Institute for Work and Health, Amster- Psychosocial Job Assessment Instrumentdam; Benjamin Amick, The Health Institute, New EnglandMedical Center, Boston. Instrument Overview The Job Content Questionnaire (JCQ) is copyrighted.Users should request the instrument from the JCQ Center The JCQ is a self-administered instrument de-(see the JCQ UsagePolicy section). The JCQ is provided signed to measure social and psychological character-with research documentation to most users free of charge,but commercial and very large research projects pay a usage istics of jobs. The best-known scales--(a) decisionfee to support comparative reliability analysis and instru- latitude, (b) psychological demands, and (c) socialment development on a nonprofit basis through the JCQ support--are used to measure the high-demand/low-Center, University of Massachusetts Lowell. control/low-support model of job strain development. Correspondence concerning this article should be ad- The demand/control model predicts, first, stress-relateddressed to Robert Karasek, Department of Work Environ-ment, University of Massachusetts, Lowell, Massachusetts risk and, second, active-passive behavioral correlates of01854. jobs. Other aspects of work demands are assessed as well: 322
  2. 2. SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE 323(d) physical demands and (e) job insecurity. The psychological strain occur when the psychologicalinstrument has a recommended length of 49 questions. demands are high and the workers decision latitude All scales can be used for microlevel, job- is low: job strain. Low social support at work furthercharacteristic analytic purposes, such as assessing the increases risk. A second set of hypotheses, related torelative risks of individuals exposures to different what might be called good stress, involves activework settings to predict job-related illness develop- behavior development under conditions of highment, psychological distress, coronary heart disease, demands and high decision latitude, which predictmusculoskeletal disease, and reproductive disorders. motivation, new learning behaviors, and copingThe scales also allow testing of hypotheses about pattern development (of course, the active behavioractivation, worker motivation, and job satisfaction hypotheses are contingent on demands not being tooand have been used for such studies. The conceptual high). The reverse is predicted for low demandsframework underlying the JCQ allows its application coupled with low decision latitude: a very unmotivat-in social policy as a measure of work quality ing job setting leading to negative job learning or(Karasek, 1998), in addition to the more commonly gradual loss of previously acquired skills.assessed work quantity issues: wages, hours, and A dynamic version of the model integrates the jobbenefits. Broader economic development issues of strain and active behavior hypotheses with personal-skill utilization as well as social costs of market-based ity characteristics measuring accumulated strain andeconomic development are beginning to be addressed self-esteem development (Karasek & Theorell, 1990)(Karasek & Theorell, 1990) using the instrument. No with the goal of predicting strain development andpersonality orientation scales or measures of non-job learning over time. The model is based on measuresstressors are included--two areas in which the user of psychological demands of work combined with amay want to supplement the instrument. measure of task control and skill use (decision The JCQ has been translated into over a dozen latitude). The psychological demand dimension re-languages. The instrument is nationally standardiz- lates to "how hard workers work" (mental work load;able by detailed occupation in several countries, Meshkati, Hancock, & Rahami, 1990), organizationproviding an occupational scoring system. An active constraints on task completion, and conflictingusers group supports usage of the JCQ, and an demands. It includes subscales shown in Table 1international board of researchers decides on policy (Subscales 2a, 2b; see Karasek & Theorell, 1990).and development issues. The "recommended version" includes additional specific measures of cognitive workload (Subscaies 2c, 2d). JCQ Scales and Their Theoretical Bases The JCQ arose out of the adaptive response toserve the new empirically based areas of social Scales la and lb: Components of Decisionepidemiology, behavioral medicine, and psychosocial Latitude--Skill Discretion and Decisionjob analysis, requiring a multidisciplinary theoretical Authoritymodel. Because the primary theoretical model uponwhich the JCQ is based and discussions of alternative The workers control over the performance of hisscale formulations in its domain are extensively or her own job is measured by two theoreticallyreviewed elsewhere (de Jonge & Kompier, 1997; distinct subdimensions of decision latitude that areKarasek, 1979, 1997; Karasek & Theorell, 1990; usually highly correlated: skill discretion and deci-Kristensen, 1995, 1996; Landsbergis, SchnaU, War- sion authority (Karasek & Theorell, 1990). Skillren, Schwartz, & Pickering, 1994), this article only discretion (Subscale la) is measured by a set ofpresents outlines of those arguments by way of an questions that assess the level of skill and creativityintroduction to the JCQ scales. required on the job and the flexibility permitted the worker in deciding what skills to employ (similar to variety; e.g., Hackman & Lawler, 1971). A secondScale 1: Decision Latitude and Scale 2: subdimension, decision authority (Subscale lb),Psychological Demands assesses the organizationally mediated possibilities for workers to make decisions about their work The most commonly used demand/control model (autonomy; e.g., Hackman & Lawler, 1971). Ahypothesis (Karasek, 1979, 1997; Karasek & Theo- question on skills required by the job allowsrell, 1990) predicts that the most adverse reactions of assessment of skill underutilization (Subscale lc). A
  3. 3. 324 KARASEK El" AL.Table 1Scales and Numbers of Questions in the Full Recommended JCQ and the "Core QES" Scale Core QES JCQ Full recommended JCQ1. Decision latitude a. Skill discretion 6 6 b. Decision authority 3 3 c. Skill underufilization 2b 2b d. Work group decision authority (new) 3 e. Formal authority (new) 2 f. Union/representative influence (new) 32. Psychological demands and mental workload a. General psychological demands 4 5 b. Role ambiguity 1 1 c. Concentration (new) 1 d. Mental work disruption (new) 23. Social support a. Socioemotional (coworker) 2 2 b. Instrumental (coworker) 2 2 c. Socioemotional (supervisor) 2 2 d. Instrumental (supervisor) 2 3 e. Hostility (coworker) (new) 1 f. Hostility (supervisor) (new) 14. Physical demands a. General physical loading 1 1 b. Isometric load (new) 2 c. Aerobic load (new) 25. Job insecurity a. Generaijob insecurity 3 4 b. Skill obsolescence (new) 2Total que~ions 27 49Note. JCQ = Job Content Questionnaire; QES = Quality of Employment Surveys.a Eight new scales/dimensions and additional items were added to make the Recommended JCQ format. b Education wasalso used in this scale.third, macrolevel component of decision latitude high demand and high control, has high-prestigeassesses the possibility of participatory influence on occupations: public officials, physicians, engineers,organization level issues, as well as union and nurses, and managers of all kinds. The passive jobwork-group participation (Subscales ld, le, If). quadrant (lower left), with low demands and low The JCQ integrates use of both individual and control, has clerical workers such as billing clerks,occupation-based conceptions of job characteristics. and low-status service personnel such as janitors. TheThe occupation-based job characteristic assessments high-strain quadrant (lower right), with high demandsyield an effective communication tool for interpreting and low control, has machine-paced operatives suchthe meaning of the otherwise abstract psychosocial as assemblers, cutting operatives, freight handlers, asJCQ scales in terms of specific jobs situations, and well as other low-status service operatives such asprovide a source of validating information about job waiters. Occupations with high percentages ofsituations. As an example: When the two JCQ job women are frequent (garment stitchers, waitresses,characteristic scales---decision latitude and psycho-logical demands--are arrayed as a four-quadrant telephone operators, and other nurses aides). Low-diagram, they define the strain and active behavior strain self-paced occupations (upper left) oftenhypotheses of the demand/control model. These can involve significant training and self-pacing, such asbe used to display (see Figure 1) average job repairmen, linemen, and natural scientists. Kristensencharacteristics of occupations in U.S. Census occupa- (1996) reconceptualized the four quadrants abovetion codes and the U.S. Quality of Employment respectively as qualified work, surveillance work,Surveys (QES) database (Karasek & Theorell, 1990). tempo work, and craftsmans work. KristensenIn Figure 1, the active job quadrant (upper right) with identified the linkages to structural and technological
  4. 4. Decision l Ltit:dAichite_Lc t Engineer • Natural Programmer Farmer O Scientist • ~]~ Teacher--H.S. • Publc WIFManager-trade • Officials • Physician +0.50 Bank Officer • Lineman • Clerk • Foreman Supervisor O Repairman..~ O Nurse I I o_Machinist • Carpenter 050 / +0.5~ Psychological Demands k- 1 I I I il~ Fireman t Stationary • Health • Off. Computer • EngineerA~ I Technician Operator _ WBilling Clerk ~lhDeliveryman• Watchman WSales Clerk I • Dispatcher -0.5o- • Gas Station O Janitor Attendant • Cutting tWaitress • Miner - OperativeO Nurses Aide O • Freight handler Construction • Telephone Laborer Operator/,f--~ " " Keypuncher / Si t n t ~ ~ /Gm a ~gh O ae r~ stitcher,-,,~.,~ O Assembler- electric/trans, mfg. Figure I. The occupational distribution of psychological demands and decision latitude (U.S. male and female workers; N = 4,495). From "The Political Impfications of Psychosocial Work Redesign: A Model of the Psychosocial Class S~ucture" (p. 177), by R. A. Karasek, in J. V. Johnson and G. Johansson (Eds.), The Psychosocial Work Environment: Work Organization, Democratization, andHealth, 1991, Amityville, N-Y:Baywood. Copyright 1989 by Baywood Publishing Company. Reprinted with permission.
  5. 5. 326 KARASEK ET AL.developments in production processes, thus making it the Job Insecurity Scale section) because specificmore useful in job redesign contexts. events of unemployment are relatively low frequency, even when the fear of job insecurity can be moreScale 3: Social Support widely experienced (Subscale 5a). The job insecurity effect can depend on the labor market requirements The demand/control model has been expanded by for particular skills, limiting future career develop-Johnson (Johnson, 1986; Johnson & Hall, 1988) with ment possibilities (Subscale 5b).the addition of social support as a third dimension.The primary hypothesis, that jobs which are high in Theoretical Interpretation of Scalesdemands, low in control, and also low in socialsupport at work carry the highest risk of illness, has and Implications: Sociologicalbeen empirically successful in a number of chronic and Psychological Originsdisease studies (Johnson, 1989; Karasek & Theorell, The JCQ provides advantages to researchers by1990). Karasek and Theorell (1990), Karasek, Trian- integrating strengths of multiple disciplines. How-tis, and Chaudhry (1982), and Johnson and Hall ever, it also presents the JCQ users with the challenge(1988) discussed the differential impacts of support of reconcifing multiple scientific literaanes when findingsfrom coworkers and from supervisors and, within are reported. We briefly outline major linkages below.these, the separate impacts of instrumental and The primary hypotheses of the JCQ, resulting fromsocioemotional support, respectively (Subscales 3a, the demand/control model, are both psychological3b, 3c, 3d). Interpersonal hostility is also included as a and sociological in nature and methodology. The JCQmeasure of social support deficit (Subscales 3e, 3f). The is sociological in that it presumes existence ofsocial support addition acknowledges the need of any socially "objective" environments that systemati-theory of job stress and behavior development to assess cally affect individual well-being and behavior. Theresocial relations at the workplace. is a focus on (a) major social institutional settings, (b) broad population groups, (c) covariance of measuresScale 4: Physical Demands with major demographic categories, and (d) its hypotheses, which evolved from sociological life The "demanding costs" of work activity are not stress and illness as well as work alienation traditions.just mental but also physical. Indeed, the more Also, consistent with much sociological literature,traditional concept of workloads involves physical associations are usually controlled for social class (forloads. Physiological effects of stress on the cardiovas- contrasting perspectives, see Ganster & Schaubroeck,cular system, the effectiveness of mental functioning, 1991; Karasek & Theorell, 1990).and general fatigue are shown in much research However, there are also differences with classicliterature to depend on both mental and physical sociological approaches. The JCQ is based on aloads, and thus this measure is also included in the theoretical foundation that implies an alternative,JCQ. Although the original QES questionnaire psychosocial class model, which appears to predictcontains only a single item on physical exertion health outcomes more effectively than the conven-(Subseale 4a), the recommended form of the JCQ tional class model (Karasek, 1997, 1998; Karasek &includes static (Subscale 4b) as well as dynamic Theorell, 1990, chapters 5, 9, 10). Kristensen (1996)physical loads (Subscale 4c), both shown to be and Karasek and Theorell (1990) noted that the scalesimportant for musculoskeletal disorder development. and methods also lend themselves to understanding of the social and technological structure of productionScale 5: Job Insecurity processes. Such associations allow interpretation of JCQ findings for human capital and economic Works psychological burden consists not only of development studies.the work of carrying out the task but also in the A variety of methodological techniques from bothhuman costs of adapting to labor market dynamics. sociology and psychometrics are used: scale reliabil-These have become increasingly important in the last ity analysis, scale construction techniques, multilevelseveral years, because the global economy has had causal analyses, and data reduction techniques suchjob-displacing effects in many countries and in- as factor analysis. The JCQ uses sociologicalcreased reported job insecurity (Lohr, 1996). Measure- questionnaire assessment methods to collect validment of these items poses statistical challenges (see data on social environments. The JCQ occupation
  6. 6. SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE 327approach uses the workers occupation as an alterna- Empirical Basis of JCQ Scale Developmenttive unit of analysis to the individuals own jobreports, allowing linkage to other insights available Origin: Stage IfPre-1984for occupational experience. The JCQ has developed in stages. Historically, the The JCQ also reflects a psychological focus and is origin of the instrument, which predates the "recom-probably used more often by psychologists than by mended version JCQ" in 1985, involved analyses ofsociologists. It addresses classic psychological topics broad pools of job characteristic survey data in twosuch as the behavioral basis for emotion-driven countries. The core questions for the JCQ scales arepsychological distress, psychosomatic illness develop- taken from the three nationally representative samplesment, and changes in microlevel behavior related to of the much analyzed QES gathered by the Universitysocial situations. There is a presumption that psycho- of Michigan Survey Research Center in 1969, 1972,social experiences are a major determinant of health and 1977 for the U.S. Department of Labor. Each ofand well-being, mediated by the neurophysiological the three QES surveys was eclectically designed andmechanisms, as well as behavioral pathways. surveyed over 1,000 aspects of work experience, in a Psychologically, the JCQ--demand/control method manner often using different questions from survey toreflects a stimulus approach, as opposed to a survey. Our research group (Karasek et al., 1988;relational approach, which emphasizes personal Schwartz, Pieper, & Karasek, 1988) conductedcognitive interpretation of the person-environment extensive statistical analyses, analyses of theoreticalrelationship. The JCQ assumes that behavior is, to a coherence, and analyses of individual questionssignificant extent, generated by social environments predicting efficiency for these large groups ofand their constraints outside the individual. The questions in the early 1980s. These confirmed thatcognitive psychological claim that decision choices major aspects of the core content of the psychosocialconstitute the primary mental workload is contrary to work experience could be captured by the smallthe demand/control hypothesis that social demands number of QES questions. On this basis, a smallare moderated by the behavioral degree of freedom subset of the questions was selected to create the Jobthat decision opportunities present (Karasek, 1997). Characteristic Linkage System (Schwartz et al.,The JCQ-demand/control approach also often treats 1988). Approximately two thirds of the linkageemotional response as a dependent variable derived system questions were sufficiently similar (withfrom work-related behaviorial requirements. minor adaptations and corrections) across the years to There are also significant congruencies with yield common assessment of absolute scale scores: apsychophysiology, as well as some differences in QES-based JCQ "core" (see Table 1, column 2). Thefocus. Most previous stress theories were developed three QES survey question sets had 27 questions into describe reactions to "inevitable" acute stress in common in the psychosocial area, which allowed development of a pooled sample of all 4,900situations threatening biological survival (Cannon, respondents, still by far the largest nationally 1914; Seyle, 1936/1976). The demand/control model representative U.S. data set on psychosocial jobwas, however, developed for work environments in characteristics. This core serves as the source ofwhich stressors are chronic, not initially life threaten- standard score data for JCQ occupational mean scoresing, and are the products of sophisticated human and a basis for time-related comparisons in the scalesorganizational decision making. The controllability of (statistical reliability is discussed in Karasek &the stressor was found to be important and appears to Theorell, 1990, Appendix 1).have become even more important as we develop The validation for the utility of such scales waseven more complex demands and limitations on also developed from a similar set of questions inindividual behavior. However, significant consistency longitudinal, Swedish nationally representative data-with classic psychophysiology is demonstrated by bases, which could be analyzed extensively forFrankenhaeuser and Johanssons (1986) psychologi- covariations with other social and individual datacal research, which shows the congruence of two (Karasek, 1976, 1979; Karasek & TheoreU, 1990) andprimary patterns of physiological response (adrena- which had extensive health outcome data. Theseline related and cortisol related) with the main analyses, while confirming the demand/control modelhypotheses of the demand/control model--allowing utility, also illuminated the importance of demo-linkage among physiological response, social situa- graphic, occupational, and social relations data, andtion, and emotional response patterns. broadly assessed work demand and hazard data
  7. 7. 328 KARASEK ET AL.(Karasek et al., 1981; Karasek, Schwartz, & Pieper, should assess a single underlying theoretical con-1983) and implied that a future measurement struct. In JCQ design, true statistical reliability isinstrument should not be restricted to the demand/ sometimes balanced against a goal of a specificcontrol task questions alone. content interpretability. Thus, the scales are also composed of subscales with separate interpretability (see Table 1 and discussion above), a goal whichStage II: JCQ Recommended Version--1985 competes with scale statistical reliability. The ques- The next stage was the development of the JCQ tions should also be standardizable questions. TheRecommended Version 1.1 in response to request for JCQ has also had the goal of covering the mostan instrument to assess the psychosocial hypotheses important aspects of qualitative work situations with aand demand/control models. This is the current small enough number of scales that the interactionsversion of the instrument. The design of the current between the scales can be feasibly examined.JCQ was initiated by request from the U.S. NationalHeart, Lung and Blood Institutes request for scales Toward "Objective "Assessment:for the U.S. Framingham Offspring Study. The JCQ Rating Versus Evaluationauthors were aware of the length limitations posed byresearch teams in national survey designs and the An important goal of the JCQ is gatheringhesitancy of other researchers adopting question sets "objective" data about work environments relevantnot of their own design, thus, the design of the new for prevention-oriented goals of improving social andJCQ instrument in 1984 focused on a very short, psychological working conditions. The Swedishefficient questionnaire that could be self-administered Level of Living Survey (Johansson, 1971) was ain 15 rain, with minimal participant guidance. methodological guide: The bias in the questionnaire The original QES core was not theoretically precise response by the participant, while inevitable, wasin several areas (particularly psychological and designed to be minimized. The questions are designedphysical demands). To add precision to the theoretical to report about, but not evaluate, the participantsconstructs of the QES core, to expand theoretical usual or main job. Thus, the JCQ questions use simplecoverage of both psychological and physical de- language so there are meaningful responses possiblemands, to expand job insecurity and social support by all employed respondents, presented in a languagescale coverage, and to assist in discriminant validity, simple enough to be understood by participants at allwe included additional newly drafted questions (see education levels. The response set is designed toTable 1, column 1) to the QES questions, yielding the assess the validity of the statement about the workpresent set of scales used in the JCQ data sets. These environment on a 4-point scale, facilitating theexpansions formed the Recommended JCQ Instru- similar quantitative weighting of questions.ment Version (see Table 1, column 2), with 49 Use of participants own questionnaire reportsquestions, which is the most commonly used version about their jobs, of course, automatically introduces(14 additional new questions and 8 additional QES self-perceptions--the source of the major critique ofquestions had been added beyond the original core). validity of instruments such as the JCQ (see theAdditional question sets cover physical work hazards, Implication for Broad Interpretability of Psychoso-computer interfaces, customer interaction, and psycho- cial JCQs section). In many cases, self-reports on joblogical strain scales. An update of the recommended conditions are the only feasible information-gatheringversion in 1995 (Version 1.5) included pilot versions strategy about workers detailed social workingof a set of global economy questions and more conditions. For example, it would take an outsidestandardizable psychological strain scales. observer much time to understand the social support situation of the worker. Frese and Zapft (1988)JCQ Focus and Scale Design Criteria claimed that the risk of self-report bias depends on the degree to which the questions require a complex The multiple goals underlying JCQ construction burden of evaluative cognition by the participant. Theintroduce competing design criteria: (a) standard JCQ objective assessment goal means that thescale reliability assessment, (b) coverage breadth, (c) questions attempt to minimize this self-reflexivescale length economy, (d) scale number economy, and component: They report about jobs, but minimize(e) specific content interpretability. A pure concept of evaluation of them. Questions of the type "lack ofstatistical reliability means that a set of questions decision making is important for me" and "the time
  8. 8. SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE 329pressures are too much for me" are replaced by The same occupational basis that provides thequestions that emphasize simple assessments of standardized scores is also the basis of an oftenenvironmental conditions only, such as: "I have utilized occupational score linkage system (Schwartzfreedom to make decisions about my job" and "My et al., 1988). The JCQ job characteristic scales can bejob requires I work fast." Such linguistic distinctions linked to other databases through U.S. three-digithave been considered quite significant in other census occupation codes (1970) and also to four-digitpsychological research contexts: for example, state- U.S. Standard Industrial Classification (industrytrait response differentiations based on phrasing classification) codes. This database linkage systemdifferences such as "Today I feel angry" versus "I allows psychosocial job content scores to be associ-usually feel angry." ated with health and productivity outcomes in Sources of difficulty remain, however. Self- national or company databases already in existencereflexive judgments remain in two psychological (such as U.S. Census, Commerce, or U.S. Nationaldemand questions: "work hard" and "work fast" (see Center for Health Statistics data), for which directAppendix A). Also, the JCQ goal of broad coverage questionnaire data collection would not be feasible.on jobs characteristics with a short set of questionsmeans that many questions elicit summary judgments Aggregate Scoring Methods for Work Groupsabout some quality of the job (skill requirements,decision possibilities). Questions about more specific Bias of findings could potentially occur withjob situations could avoid this problem, but would self-reported psychosocial work environment andlikely make the questionnaire longer or the questions dependent variables such as depression, exhaustion,unjudgable by some respondents, and therefore the and dissatisfaction (see the Implications for Broadresponses difficult to compare across groups. Interpretability of Psychosocial JCQs section). One remedy is to aggregate self-report responses by work groups with similar work situations, thus dilutingOccupation-Based Analysis individual biases (Kristensen, 1996). This is, ofand Score Standardization course, the basis of the occupation database linkage In addition to direct administration of JCQ system suggested above, but systems of mixedquestionnaires to workers, the JCQ system offers a self-report and work-group aggregated assessmentsecond set of occupation-based methodologies. There have also been successfully applied (Vahtera, Pentti,is an extensive system of JCQ scores scales by & Uutela, 1996).detailed occupation and gender in several countries The alternative of expert observations is certainlythat is the basis of (a) the JCQ occupational score theoretically desirable, but in practice it has problems.standardization system and (b) the occupational Expert observations are costly, time consuming, andlinkage system. in assessment of social interactions do not obviously Detailed scoring procedures for the JCQ scales are generate more accurate measures resulting in lowdescribed in the JCQ Questionnaire and Users Guide interrater reliability. There are also theoretical biases(Karasek, 1985). Most of the scales have been involved in the very concept of standard "expert"standardized by detailed occupation codes for several measures: It is much easier to measure the easilynational populations (for the U.S. population: Karasek observed, repetitive quality of the low-status assembly-& Theorell, 1990, Appendix; Schwartz et al., 1988; line jobs than the diverse tasks of nigh-statuswith related scales standardized in Sweden [work managers or professionals. Thus, measurement reli-exposure matrix: Johnson & Johansson, 1991; ability for the most potent set of psychosocial jobJohnson & Stewart, 1993]). The JCQ questions can be characteristics (decision latitude, skill, and decisioncompared to national scale scores for detailed census autonomy) is probably correlated with scale level--acode by sex and by four-digit industry code. This complex confounding of content and validity (for allallows unique assessment of differences between a methodologies, not just the JCQ).target group and "national norms" for psychosocialjob dimensions. This allows JCQ users involved in Scale Statistical Validitypractically oriented job analyses, small populations,or single-plant studies to compare their findings with The most substantial compilation of reliabilitynational averages on the scales (broken down by sex, findings is presented in the following section (Part II).occupation, and industry). However, previous reliability analyses of the scales
  9. 9. 330 KARASEK ET AL.very similar to the JCQ scales have been published update has cataloged 41 studies of the major coronaryfor the U.S. national populations (Q.E.S. database: heart disease risk factors (blood pressure, serumKarasek & Theorell, 1990, Appendix 1; Schwartz et cholesterol, and smoking) testing associations withal., 1988). Kawakarni and Fujigaki (1996) and job strain. In over a dozen studies of blood pressureKawakami, Kobayashi, Araki, Haratani, and Furui using sophisticated ambulatory assessment technolo-(1995) published the first studies on the reliability of gies, all show either positive or mixed positiverecommended format JCQ scales (omitting physical results. However, less-sophisticated blood pressuredemands and job insecurity). The study concluded measurement technologies show no consistent associa-that the JCQ is reliable for Japanese populations and tions, and smoking and cholesterol have mixedfound Japanese occupation scale ratings that are positive and null associations.similar to those in the United States (see Appendix A). Consistent associations between mental strain andBrisson et al. (in press) showed JCQ scale reliabilities JCQ-like scales are also reported (see Bourbonnais,to be good and confirmed the scale structure Busson, Moisan, & Vezina, 1996; Karasek &(Larocque, Brisson, & Blanchet, in press) from both Theorell, 1990), but differential effects of jobrandom population survey and a white-collar survey characteristics are noted. Measures of exhaustion andfrom Quebec, Canada. A 1993 large-scale sample in burnout are more consistently associated with highthe United States (Amick, Mangione, & Wu, 1998) psychological demands, whereas depression andreported JCQ scales to be reliable, as well as scale anxiety measures are more strongly associated withstructure confirmation, but some scales differ signifi- low decision latitude.cantly from the recommended JCQ format. Sante Occupational musculoskeletal injury prediction isQuebec (1994) showed acceptable JCQ scale reliabili- reviewed by Bongers, de Winter, Kompier, andties in the Netherlands, but some factor structure Hildebrandt (1993), who found support for thedifferences arose. predictive utility of the demand/control/support model, particularly for upper extremity disorders. Many additional studies using the demand/control modelPredictive Validity and JCQ scales have been undertaken since then, including associations with pregnancy disorders It is beyond the scope of this article to review the (Brandt & Neilsen, 1992; Fenster et al., 1995)andextensive research literature using the JCQ and immune system disfunctions (Kawakami & Fujigaki,JCQ-like scales to predict illness (much research is 1996; Peters et al., 1998).based on similar, but not exactly equivalent scales).Comprehensive reviews are presented by Marmot andTheorell (1988), Kristensen (1989), Schnall and JCQ Measurement and Administrative IssuesLandbergis (1994), Kristensen (1995), Kasl (1996),and Tbeorell and Karasek (1996). However, insummary, it can be stated that the JCQ scales and JCQ AdministrationJCQ-like scales demonstrate substantial predictivevalidity with respect to stress-related chronic disease The JCQ is designed for self-administration andin international and U.S. research. has often been included as a section in other Job strain and heart disease associations constitute questionnaire instruments in which a short introduc-the broadest base of empirical support for the model. tory sentence about how to respond to the questions isJCQ scales or similar scales associate significantly included. The completion time is short, approxi-with cardiovascular mortality using a wide range of mately 15 min for the full recommended version.methodologies. Landsbergis (augmenting his earlier Professional assistance, such as the research personreview [Schnall & Landsbergis, 1994] by personal reviewing the instructions, has also often occurred.communication, December 1997) tabulated 72 pub- In addition to the standard JCQ questions, JCQlished studies of cardiovascular disease (CVD) or users are encouraged to add their own specificCVD risk factors testing associations with job strain "umbrella questions" that refer to the measurementusing JCQ-like scales. Of the 36 studies investigating of specific job conditions in the surveyed work sites.CVD or mortality, over two thirds showed positive Although the umbrella questions would differ be-associations (i.e., either all significant or mixed tween studies, they could be factor analyzed with thesignificant positive results) with job strain, and many other JCQ questions and correlated with the standardof these were positive cohort studies. Landsbergiss JCQ scales used as reference points.
  10. 10. SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE 331JCQ Breadth of Use and Scale Consistency back translation into English submitted to the JCQ Center, and a copy of the translated instrument. The instrument has been selected for large studies Adaptation of the JCQ for housework and home-of job conditions in the United States, Canada, role work, student status, and unemployment has alsoEurope, and Japan. The JCQ is being used by large been undertaken but presents challenges becausestudies in Europe (over 50,000 participants) and these less-structured social roles mean less specificJapan (over 40,000 participants) for the study of job questionnaire language. Adaptation of the JCQ forstrain, heart disease, and absenteeism. The short low-education workers and workers in less economi-length and predictive validity appear to be the major cally developed countries for Spanish-speaking work-reasons for its success. Length is mentioned as a ers has also been undertaken.crucial instrument parameter by many users (asubstantial number would like an even shorterinstrument; there is no validated shorter instrument JCQ Usage Policywith standardizable scores at present). Because of the The JCQ is copyrighted and not published in theactive international collaboration by JCQ researchers, public domain; however, it is the goal of the JCQthe effort invested bymany individual JCQ projects in Center to make it available to all researchers whothe past is now yielding collective benefits with the request it with substantial supporting documentation,development of comparative databases that further and to promote scientific development in the areaenhance the data interpretability of each study. through a users network. The JCQ Questionnaire and Users Guide and research documentation are pro-JCQ Usage Study: Compliance vided free of charge to most users. However, JCQ useWith Recommended Format by large research studies (over 750 participants) and commercial users requires payment of per-nse The JCQ has retained the same recommended charges. Registration in a JCQ users project databaseformat (Version 1.1) since 1985 (see Appendix C). To for the users network for all users and a copy of thetest the consistency of scale use and to assess the researchers JCQ and demographic data for futureutilization of the JCQ, in 1995 Robert Karasek reliability analyses (large studies only) are required.conducted a survey of all contactable JCQ users. Contact the JCQ Center, Department of WorkFrom the 246 recorded requests, 130 projects were Environment, University of Massachusetts Lowell,estimated to have been completed by that time. The Lowell, Massachusetts 01854, for details of policy,most consistently used scales are the decision latitude fees, and requirements.scales, with 85% reporting compliance with thestandard version. Psychological demands has 69% Summary of lnstrument Descriptionusing the recommended nine-question version andanother 19% using the older five-question (QES core) and Notes on Future Challengesversion. Standard version social support was used To summarize description of the instrument, we74% of the time. However, physical demands are include at this point several comments that reflectincluded in only 58% of the studies and job insecurity information in the second, empirical section of thisin only 36% of the studies. The skill utilization article.question, important for work quality policy and 1. The 1995 study of usage consistency demon-productivity outcomes, is included in 42% of these strates that the JCQ has provided a common set ofstudies. scales used with consistency throughout almost 100 studies, including large national studies, of psychoso-Translations Into Other Languages cial factors at work. This breadth of use is a unique occurrence for measurement of psychosocial work Authorized translations of the full JCQ instrument characteristics in the United States and internation-from English, which have been specifically approved ally, and it helps to overcome the major scientificand which are available from the JCQ Center, are deficit of such instruments: the lack of comparativeFrench-Canadian, French-Belgium, Flemish-Bel- assessment capability across databases (see discus-gium, Spanish, Swedish, Dutch, Italian, and Japanese. sion in Santer & Murphy, 1995).Other language translations are in process. The 2. As a result of the empirical review in theauthorized process requires requesting permission, a following section (Part II of this article), the JCQ
  11. 11. 332 KARASEK ET AL.recommended version since 1985 (and provisionally b. For psychological workload and socialaugmented in 1995) remains the "recommended support, improved scale performance may requireversion." The need to expand from the earlier "QES linguistic tool development and local consensualcore questions" is validated. In particular, some of validation of response meanings. Additional measure-these additions are crucial for continued psychosocial ment methods beyond questionnaire use involvingresearch: Job insecurity is of increasing importance observations or interview methods that can be linkedbecause of the global economy, and the physical to the JCQ are also needed. Parts of these activitiesdemand scale is of increasing importance because of may involve establishing new languages for socialthe increasing prevalence of musculoskeletal disor- policy purpose in these areas---a social advocacy task.ders in many countries. The "skill level required" c. Dropout of highly "stressed" participantsquestions (the seventh skill discretion question) is from studies, especially in more rigorous scientificcrucial for work-quality policy discussions. protocols, appears to be a much larger problem than The predictive validity of the scales, while not previously assumed and is growing as stresses ofreviewed in detail in this article, is probably the major modern life make participation in scientific studiesreason for the success of the instrument. In general, it difficult for certain groups (temporary and transitionalcan be concluded that the JCQ seems to be potentially employees, marginal economic groups in all settings,useful in capturing important elements of psychoso- and many populations outside of the developedcial experience at work in many countries, and thus industrial countries).allows an internationally comparative understanding d. Organization-level job factors are also notof "qualitative costs" and "benefits of work." studied in the JCQ, and their effects on determining On the basis of the findings of the analysis of 12 job structures appear to be significant (Warren, 1998).separate male and female populations, we can find no Whether this analysis needs to be a part of ancompelling reasons to reject the JCQ scales on the expanded JCQ or separate measurements approach,basis of inconsistency of means and standard such topics should be explored for further compara-deviations or Cronbach alpha reliability. However, tive analyses.factor analyses results noted above do raise questions e. New work patterns that involve computer-about inclusion of certain questions, a potential basis based communication, network communication, andfor future revision of the JCQ scales. mass-media communication serve as the mode of Although some of the tables in the empirical social coordination in ever larger numbers of socialreliability test (Part II of this article) are based on activities. These may require significantly alteredrestricted forms of some scales in order to ensure methodologies for assessing psychosocial workcompatibility with several older databases, the largest experience.of the new studies now being collected in Europe and f. Quantitative work aspects of work (particu-Japan include almost complete versions of all of the larly hours of work, spouse work time, income, etc.)recommended JCQ scales, which further bolsters the certainly need no proof of importance but should beutility of using the full scales in the future. simultaneously gathered and used along with JCQ 3. Although an integrated review of the JCQ scales assessments when broad policy implications are to beshortcomings and future improvement directions is understood.beyond the scope of this article, some preliminary g. Psychosocial experiences outside of work inobservations about future challenges for the JCQ can the home and community, and across the life spanbe made, reflecting both this article and the current (jointly with work experience) must be made a part ofsocial context of rapidly changing working conditions. psychosocial analytic frameworks even when work- a. The area of work quality needs to be opened place effects are the primary scientific focus.up to international political and economic policy h. The creative behavior side of psychosocialdiscussions, an important challenge given the accelera- workplace behavior needs to be given furthertion of global economic linkages. JCQ expansions, measurement emphasis, including social interactionssuch as the pilot versions of the JCQ global economy which make it possible. To start, more attentionscales, could assist this. Assessment of socially should be paid to existing active job hypotheses todetermined possibilities for control, demand, and facilitate further integration with the active copingsocial integration deriving from broad global eco- health and well-being research themes of psychoso-nomic changes could be assessed. cial research. This extension would also allow new
  12. 12. SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE 333forms of nonmarket productive output to be better and heart disease in U.S. and Swedish samples butassessed, and would assist comprehensive dialogue found different retrospectively reported ratings forabout costs and benefits of "the new work organiza- work and family stressors in the two countries (withtion." "Conducive economic policy" could serve as work being less important in the United States). Kaslone basis for this expansion (Karasek, 1998; Karasek (1996) speculated that the toll of unemployment and& Theorell, 1990). the nature of work in general is less important for U.S. i. Modified assessment methods for psychoso- workers than for European workers. However, thiscial working conditions in less-developed economies has not been tested with direct empirical data onmust also be integrated with existing JCQ scales individual work situations in broadly representativeusage, which has primarily focused on developed populations.countries. These must assess the relationship between Additionally, there has been much discussion ofpsychosocial work costs and benefits and more international differences in work organizational cul-conventional economic rewards and demographic tures, as when Japanese just-in-time assembly meth-transformations. ods were introduced into the United States and Europe (Berggren, 1992). One empirical investiga- tion of work organization and company policies PART 1I across seven automobile manufacturers in four countries shows that "teamwork" is very differently understood due to national (Japanese, French, Italian, International Comparison o f the JCQ and German) differences, regional, and company Scales in Four Countries culture (Frieling, Freiboth, Henniges, & Saager, 1997), although the relative magnitude of intercom- Rationale party versus intercountry sources was not assessed. Trends in working conditions show increased risks Some useful internationally comparative findingsto well-being arising from social and psychological exist for scales very similar to the JCQ. Typical ofcharacteristics of work in Europe and Japan in these findings are U.S., Swedish, and Japanese studiesreported national statistics (Dhondt, 1994, 1998; which show that the ranking of occupations onPaoli, 1997; Shimomitzu & Levi, 1992). Available decision latitude scales is very similar in the Unitedanecdotal reports in the United States in the 1990s States, Japan, and Sweden (see Appendix B).also suggest growing problems of work-relate.d Unfortunately, the utility of many studies that arepressures. Comparative assessment of these psychoso- potentially similar is limited by lack of trulycial exposures between countries in the global comparable scales in each study. In general, absoluteeconomy could open up the area of "work quality" to scale scores are important for JCQ research becauseinternational political and economic policy discus- they allow comparative analysis of national andsions. However, significant progress requires interna- occupational differences and facilitate comparativetional comparisons with standardized instruments--an formulation of some "job strain" definitions. Also,area in which progress has so far been slight. The although validation studies for the JCQ scales haveinternational comparisons would also provide an been published for some populations, the cross-important reference standard for many homogeneous national validity of the JCQ has not been systemati-population studies. These challenges motivate the cally assessed. Neither has the comparative reliabilitypresent investigation. and validity of the JCQ scales been tested separately Most international comparative analyses of work for male and female workers. Hall (1994) argued forfocus on economic outcomes. It is well known that the importance of examining womens job character-there are national differences in the distribution of istics separately. International comparisons of poten-income, with greater disparities (i.e., higher standard tial gender differences could be useful because femaledeviations) occurring in the United States between labor participation patterns vary significantly byhigh and low incomes than in Canada, Europe, or COuntry.Japan. Furthermore, these disparities have increased From a psychometric perspective, the process ofin recent years in the United States. scale validation will often examine scale reliability Similar differences might be expected for psycho- statistics across multiple populations, with thesocial job characteristics. For example, Orth-Gomer presumption that the scale should perform in a similar(1979) reported similar associations between stress manner across populations. Differences between the
  13. 13. 334 KARASEK ET AL.populations themselves are not the focus. However, Methodfrom a sociological perspective, the populationdifferences or similarities are of interest. We will also Populationsfollow psychometric tradition and assess the consis-tency of the scale performance across populations. In The six populations studied come from the United Statesthe case of job characteristics, the most common (2), Canada-Quebec (2), the Netherlands, and Japan (see Table 2). The number of participants in each study rangedsociological hypothesis would be that major national from 580 to 6,053 for a total of 16,601 participants (38%differences do exist in scale characteristics, because women and 62% men). The participation rates ranged fromthe JCQ reflects organizational characteristics of the 65% to 93% (see Table 2). The age boundaries span the fullmajor social institutional framework of m o d e m adult working life, age 20 to 65 (retirement age), but the Japanese samples age span is from age 20 to 60. Part-timesocieties--frameworks that have been demonstrated workers are included if work time is greater than 20 hr/weekto differ between countries from many perspectives. except for the two Canadian samples, which include only full-time workers (->35 hr/week). Two populations include the full occupational spectrum-- Objectives managers and professionals, clericals, line workers in white- and blue-collar occupations, and services workers----based The main objective of the study is to compare mean on random samples of their geographical location work-values, reliability, and validity of the JCQ scales forces: (a) the U:S. QES samples from the 1970s (three separate national samples combined; see Karasek &across six studies conducted in four different Theorell, 1990, Appendix 1) and (b) the Quebec provincecountries. Complementary objectives are (a) to assess stratified random (Sante-Quebec, 1994) sample from 1990.the extent of similarities and differences found under Three other samples are broadly inclusive of the fullrelatively different national contexts (the United occupational spectrum from manager to line worker: theStates, Quebec-Canada, the Netherlands, and Japan); more recent U.S. New England Medical Center (NEMC) sample, the Dutch sample, and the Japanese sample. The(b) to assess potential differences by gender; and (c) U.S. NEMC data include representative samples from allto compare these differences to published findings status levels in 16 large U.S. workplaces in sevenabout scale differences due to occupation. corporations (full samples of 12 middle-sized workplacesTable 2Population Definition for the Studies Participant Study country Date N % instrument Population typeU.S. QES 1970s 4,319 73 QES/JCQ National random population sample M = 2841 F = 1478U.S. NEMC 1994 6,053 71 Base JCQ (modified) a Broadly representative: 16 large employers, blue and white collar M = 3676 F = 2377Canada-Quebec 1990 1,232 77 Full JCQ (minus)b Provincial, stratified random M = 707 population sample F = 525Canada-Quebec-white 1994 2,666 73e Full JCQ (minus)b Regional, 8 companies collar only M = 1364 65a F = 1302Netherlands 1994 1,751 86 Full JCQ Broadly representative: 34 compa- M = 1228 hies, blue and white collar (limited F = 523 job mobility/variety)Japan 1993 580 93 Full JCQ (minus) b 2 companies, blue and white collar M = 472 F = 108Note. QES = Quality of Employment Surveys; JCQ = Job Content Questionnaire; NEMC = New England MedicalCenter; M = male; F = female.a Some signlficandy different scales.b Minus some scales.¢ Participation for the full population who completed the psychological demands and decision latitude scales.d Participation for the population who completed also the social support scales.
  14. 14. SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE 335and random samples of 4 very large workplaces, representa- researcher sent the tabulated data to RK, who constructedtive of the U.S. workforce in many respects) but omit the final tables.workers in smaller companies, a lesser fraction of theworkforce. The Dutch sample includes white- and blue-collar workers from 34 companies, across a range of Analysescompany sizes and industry branches. It deviates fromrandom selection in that only workers with relatively fixed All analyses were conducted separately for women andwork locations and a limited number of tasks were selected men in the six populations. Mean values and standardto facilitate physical ergonomic job assessments (however, deviations of each scale were calculated. We used anthis does not exclude professionals such as teachers, nurses, analysis of variance (ANOVA) to evaluate statisticaland some managers). The Japanese sample (Haratani et al., differences between scale means across populations. Given 1997) includes white- and blue-collar workers from two that the samples are large, statistically significant differencescompanies with fairly technically sophisticated output between means across populations are expected even for(telecommunications and power utility). The sixth sample, the small and potentially nonmeaningful differences. Therefore,second Canadian database from Quebec, is conapesed of only the proportion of variance explained by the study site waswhite-collm workers employed in eight white-collar organiza- presented to quantify the magnitude of the variationstions engaged in semipublic, public, or private service activities. between means. Reliability of the scales was assessed by the internal consistency as measured by the Cronbachs alpha coefficients. Concurrent validity was assessed by correla- Instrument tions between scales and subscales and by correlation of scales with age a n d education. To assess variability in correlation coefficients, we computed range and mean Our intent was to use the full recommended JCQ scales correlations across the six samples. A simple scale was used(Karasek, 1985). However, some questions were missing in to quantify variability on the basis of the range of correlationsome of the older studies. Therefore, the "lowest common coefficients among the six populations: L = low variabilitydenominator of questions" was found to maximize compara- (i.e., a difference between the highest and the lowesttive possibilities. For psychological demands, the five- correlations coefficients < .20); M = moderate variabilityquestion QES version is used, because the full nine-question (i.e., a difference that varies from .20 to .35); and H = highversion was only available in four of the studies (for all variability (i.e., a difference > .35).correlations, separate tabulations have been made for the full Some factorial validity analyses conducted in thesenine-questions version). For the physical demands scale, populations axe summarized here, but no tables arealthough five of the studies had the one-question version, presented because of space limitations. The exact methodolo-only the relatively recent Dutch sample had the full gies of these analyses are not always consistent acrossrecommended five-question scale, and thus, most tabula- populations. Separate factor analyses of decision latitudetions are based on the one-question version. Only the and psychological demands; then decision latitude, psycho-Canadian sample had the five-question social support scale, logical demands, and social support; and finally, all scalesbut all of the other samples had a QES-based four-question together have been reported. Sometimes the two decisionversion, which is used in the tables. No study had the full latitude subscales and the psychological demand scale havesix-question job insecurity scale, thus a special two-question been tested as two factors, sometimes as three. All analysesversion of the scale, available in three studies (U.S. QES; were conducted using standard statistical analysis programsU.S. NEMC; and the Netherlands), was computed only for (Study 1, 5, 6; SAS Institute, 1990; and Study 2, 3, 4; Statathis article. The original English version of the JCQ was Statistical Software, 1997).used, or validated tramlafions in French (Brisson, Dion, et al.;Brisson, Larocque, et al., 1998; Larocque, Brisson, & Blanchet,in press), in Dutch (Houtman, 1995; Reuvers et al., 1998), and in Comparison of Between-Occupation VarianceJapanese (Kawakami & Fujigaki, 1996; Kawakawi et al., and Occupational Rankings1995). Although consistent coding of occupations across all the databases was not possible for this article, the use of Data Collection interoccupation differences in job characteristics present an important reference standard for assessing the relative The instrument was self-administered in most studies importance of intercountry differences. Thus, the results for(Study 1, 2, 4, 5, 6) or administered during a face-to-face the one study database that does have an interoecupationinterview (Study 3). Self-administration was usually done at ANOVA (U.S. QES) are included here, and an occupationalthe workplace. Workers were allowed by their employers to ANOVA for scales similar to the JCQ in Sweden is alsofill in the questionnaire during regular working hours. presented (Swedish scales from Johnson and Stewart, 1993;Although data on all samples had previously been collected, U.S. scales from the U.S. QES study in this article; Schwartztabulated, and in some eases published by participating et al., 1988). The Swedish analysis is based on a similarresearchers, this previous material did not always follow scale for decision latitude; however, the support scale inexact JCQ guidelines or was not presented in a comparable Sweden is only a "possibility-of" assessment (mainlymanner. Therefore, for the parpose of the present article, one instrumental) and only for coworkers. Also, the Swedishof us (RK) requested participating researchers to retabulate psychological demand scale is assessed more subjectivelydata following defined JCQ guidelines (as modified above) and has fewer questions than the U.S. scales. Theto allow meaningful comparisons. Each participating between-occupation variance reported is a percentage of the
  15. 15. 336 KARASEK ET AL.Cronbach alpha reliable scale variance (this represents For psychological demands (five items), the U.S.between .60 and .75 of the total variance for the Swedish NEMC womens population is higher than others, butscales). An additional person-based demographic contribu-tion to psychosocial scales between occupation is also otherwise there are no major deviations for men orreported in both U.S. and Swedish studies. This addition women on this scale. The physical demands scaleincreases the variance somewhat, of course, not because of does not show consistently higher levels for men thanthe job alone, but because of the interaction of person and for women. It shows a substantially lower level in thejob (e.g., the additional effect of age on the decisionanthority of managers). This effect is roughly corrected for U.S. NEMC sample than in the U.S. QES sample. Thein the Swedish sample by assuming the same average job insecurity scale (based on the specially calculatedcontributions from demographics in Sweden as in the United comparable subscale across populations) shows aStates, averaged across scales. substantially higher level in the 1990s in the United The rankings of occupations on the JCQ decision latitudescale are compared for the seven occupations reported in States than it did in the 1970s.Kawakami et al.s (1995) two-company study, compared One highly consistent finding observed in allwith the JCQ scale rankings of the same occupations in the studies is the gender differences in skill discretion andU.S. and Swedish nationally random samples, The U.S. and decision authority. Indeed, women have consistentlyJapanese studies use the JCQ scales reported in this study,whereas a similar, non-JCQ scale is used in Sweden lower scale means for both these subscales. These(Johnson, Stewart, Friediund, Hall, & Theorell, 1990). gender differences tend to be smaller in the Quebec stratified random population sample than in the other samples. The gender differences average about a Results quarter of the populations standard deviation. The scale standard deviations are generally higher,Means and Standard Deviations of JCQ Scales as would be expected in the first three populations, which have broadly representative samples, than in The means are very similar across studies (see others in which restrictions of populations do occur,Table 3). Although the difference between means are for both men and women. In three representativestatistically significant among the studies for all samples, the standard deviations are very similar onscales, the proportions of the variance of scale scores all scales.explained by study site are small, that is, generallyless than 5% for men and women for the more reliablescales. Within men samples, the proportions ex- Internal Consistency of JCQ Scalesplained ranged from 1% to 4% for decision latitude,psychological demands, supervisor support, and Internal consistency of the scales tend to be similarcoworker support (averaging 2.5%). These propor- across populations and between men and women (seetions were, respectively, 6% and 9% for physical Table 4). The Cronbachs alpha coefficients aredemands and job insecurity, where only three studies generally acceptable (overall average alpha forhave data and there are reliability limitations for the women is .73 and for men is .74). The highest andscale forms included in the study. Within women most acceptable values of the coefficients are foundsamples, the proportions explained ranged from 3% for the decision latitude, physical demands, supervi-to 10% for decision latitude, psychological demands, sor support, and coworker support scales. However,job insecurity, supervisor support, and coworker the psychological demands scale, with five questions,support (averaging 4.8%), whereas it was much is only borderline (Nunnaly & Bernstein, 1994).greater (17%) for the single-question physical de-mand scale. Some minor deviations occur for the skill discretion Although differences between samples are gener- scale, which falls to borderline levels in the Dutchally small, some specific tendencies can be observed. study for men and women and for the decisionThe decision latitude means are the highest in the two authority scale for men. However, taken as a singleQuebec samples for both men and women. The scale, the decision latitude scale has quite acceptabledecision latitude means and more specifically the coefficients. The skill discretion scale has a lowdecision authority means are lower in the U.S. QES reliability for Japanese men but is acceptable for(1970s) sample than in the U.S. NEMC (1994) Japanese women. Decision latitude has good reliabil-sample for both men and women. The decision ity in Japanese women but remains low for men. Thelatitude means are the lowest in Japan and U.S. QES job insecurity scale also has low coefficients in two(1970) in both men and women, although for women, out of the three populations for which data arethe Netherlands sample is as low as Japans. available.
  16. 16. SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE 337 ~ ~ I I ~ 0 z ~~11~ II " ~v ~ ~ ~.~ ~ °c~ ~,~.~ ~ . ~~ ~ ~
  17. 17. 338 KARASEK ET AL.Table 4Cronbach s Alpha Reliability Coefficients of the Job Content Questionnaire ScalesAmong Men and Women in Six Samples Study sample U.S. U,S. Canada- Canada- Scale QES NEMC Quebec Quebec-W Netherlands Japan M MenSkill discretion .75 .79 .79 .80 .67 .59 .732Decision authority .69 .70 .71 .70 .61 .66 .678Decision latitude .83 .84 .86 .86 .77 .68 .807Psychological demands (9 items) -- -- .68 .75 .74 .72 .723Psychological demands (5 items) .63 .71 .59 .67 .57 .61 .630Physical demands NA NA -- -- .86b -- .860Job insecurity .60a .74 -- -- .49 -- .610Supervisor support .85 .80 -- .82 .83 .89 .838Coworker support .80 .72 -- .72 .78 .74 .752 WomenSkill discretion .71 .75 .78 .79 .65 .80 .747Decision authority .72 .64 .70 .63 .70 .68 .678Decision latitude .80 .81 .85 .84 .77 .84 .818Psychological demands (9 items) -- -- .72 .72 .69 .72 .713Psychological demands (5 items) .62 .72 .63 .64 .51 .65 .628Physical demands NA NA -- -- .79b -- .790Job insecurity .47c .76 -- -- .52 -- .583Supervisor support .83 .84 -- .83 .83 .87 .840Coworker support .81 .75 -- .69 .82 .76 .766Note. QES = Quality of Employment Surveys; NEMC = New England Medical Center; Quebec-W = white-collar only.Dashes indicate no data available.a 0.53 for the three-item scale of job insecurity, b For the five-item scale of physical demands, c 0.41 for the three-itemscale of job insecurity. Correlations Between JCQ Scales and coworker support scales, two subcomponents of and Subscales the social support scale, are correlated at .40. Generally, there is little difference in the decision The correlations between JCQ scales and subscales latitude scales two subcomponents, skill discretionrepresent 26 possible correlations (decision latitude and decision authority, in correlations with the othercorrelations with its subscales are excluded). When scales. One exception is the Japanese men for whomanalyzed separately for women and for men, these the skill discretion coefficients are three times as largeproduce a matrix of 52 possible correlations (see as the decision authority coefficients for bothTable 5). Across study populations, 33 correlations supervisor and coworker support. The decisionshow low variability, 12 show moderate variability, latitude scale correlates strongly (given moderateand 7 show high variability. In a number of cases, the scale reliability) with the two social support subcom-variability occurs from extreme values observed in ponents; it correlates moderately with psychologicalthe Japanese population (some of the idiosyncratic demands and negatively with physical work and jobJapanese findings may be due to the very small insecurity.womens sample; see below). If we exclude these The psychological demand scale displays a low andextreme values, 39 correlations (75%) have low very variable positive correlation with decisionvariability across populations. latitude for both men and women (all the high- Review of specific associations reveals the struc- variability associations are from the psychologicalture of the JCQ scale relations. Decision latitude is the demand scale). However, in the above studies, onlyadditive combination of skill discretion and decision the U.S. womens sample of the 1970s and the Dutchauthority scales, which are consistently correlated at sample shows the negative correlation, which isabout .55 for both men and women. The supervisor associated with an increased prevalence of the "job
  18. 18. SPECIAL SECTION: JOB CONTENT QUESTIONNAIRE 339strain" combination. The correlation is actually age correlations with any scale. Education has strongstrongly positive in the small sample of Japanese negative correlations with decision latitude andwomen. Correlations of psychological demands with physical demands, but low correlations otherwise.decision latitude are somewhat higher for men than There is a moderately strong and consistent negativefor women. The findings for the nine-questionversion association between age and education (about -.20)of the psychological demand scale show similar in all of the samples (which is much stronger for thevariability. Japanese women). These correlations may reflect The psychological demands scale varies across intergenerational differences in education levelspopulations in its correlation with physical demands. (lower levels for older generation workers) and theIt is strongly positive in two out of three populations broad age range (20 to 65 years) of includedwhere it is available, but very low in the third one (the participants.U.S. NEMC sample). Psychological demands has The Japanese sample has substantially differentmajor associational variability with supervisor sup- correlations of decision latitude scale with age andport: In the U.S. QES it is strongly negatively education than the other populations. There is nocorrelated, in Japan it is uncorrelated, and in other association between education and either skill discre-populations it has a low correlation. Physical tion or decision authority for the Japanese men anddemands show a consistent negative association with negative correlations for the Japanese women, but adecision latitude, and correlations are stronger for strong positive association exists in all other than for women. Job insecurity shows generally For the Japanese women, a high positive associationconsistent associations with other scales, particularly between age and psychological demands is alsoa moderately strong negative correlation with the observed. Additionally, they have a high positivedecision latitude, supervisor, and coworker support correlation between age and skill discretion and ascales. weaker negative correlation between education and Correlations between the nine-item version of the skill discretion (although this correlation reduces topsychological demands scale and other JCQ scales zero when age is adjusted; Kawakami et al., 1995).are shown in Table 6. The correlation between the Correlations of supervisor support and decisionfive-item and the nine-item versions is high (.88). The latitude with education are also very small for thevariability of associations with other scales remains Japanese sample but are strongly positive for thewith the nine-item version (among the four popula- other samples.tions for which it is available). The nine-item version Several consistent gender-related exceptions arehas a more positive overall correlation with decision observed. Demands are in general more consistentlylatitude. related to decision latitude for men than for women: The physical demands scale displays a low and Physical demands are more highly negatively corre-variable positive correlation with job insecurity for lated with decision latitude and education for men,both men and women and a low and negative and psychological demand associations with decisioncorrelation with supervisor and coworker support, latitude are somewhat higher for men than forexcept for the U.S. QES womens sample and the women. Physical demands are more highly negativelyJapanese womens sample. correlated with education for men than for women, and psychological demands are negatively correlated with age for men, except for the Dutch sample, but Correlations of JCQ Scales With weaker for women, except for the Japanese sample Age and Education and for one Canadian sample, in which correlations for men and women are nearly the same. Correlations of JCQ scales with age and educationrepresent 32 possible correlations (see Table 7). Ofthese, 16 display low variability across populations, Factorial Validity of JCQ Scales10 show moderate variability,and 6 show high variability.Here particularly, extreme values are observed in the The U.S. population from the 1970s shows a clearJapanese sample. After excluding them, 26 correla- factor pattern corresponding to the JCQ scales fortions (81%) have low variability across populations. men (which is not surprising because this was the The correlations with age and education are, in JCQ defining base sample) and also for women. Alsogeneral, lower than those observed between the JCQ in the United States, the NEMC sample from the earlyscales and subscales themselves. There are no strong 1990s shows a confirming pattern for most factors for
  19. 19. 340 KARASEK ET AL. x_. @ I I I I I ~t 4t I i I I I I I I I I I il I I I i I ..~ k. k. i I I I I I I I ~CYZ