Smoking Risk factors

777 views

Published on

This document provides an impressive and elaborated risk factors that usually contribute to smoking and often went unrecognizable from a naked eye, with psychological, social and environmental perspective

Published in: Health & Medicine
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
777
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
7
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Smoking Risk factors

  1. 1. SMOKING: RISK FACTORS AND INTERVENTIONS 1 Risk Factors for Smoking By the age of 18, more than two-thirds of teenagers have experimented with cigarette smoking with peak experimentation occurring between 13 and 16 years of age (USDHHS, 1994; Duncan et al., 1995). Initiation and maintenance of tobacco during adolescence is influenced by interplay of psychosocial, biological and environmental factors (USDHHS, 1994). A summary of these factors is presented in the given table Psychosocial Factors Sociodemographic Personal and Interpersonal Attitudes/ Expectations/Perception Psychobiological Factors Positive Reinforcement Body Weight Control Addiction PsychologicalFactors Affective Regulation Cognitive Enhancement EnvironmentalFactors Socioeconomic Status Media Psychosocial Factors Psychosocial factors are the most widely studied variables that directly and indirectly affect an individual‟s choice to use tobacco. Given that young people are particularly vulnerable to psychosocial influences, prevention efforts to reduce smoking, must seriously take these factors into consideration. These psychosocial factors appear to have the greatest influences on smoking initiation and maintenance.
  2. 2. SMOKING: RISK FACTORS AND INTERVENTIONS 2 Sociodemographic Factors Age The specific development stage of adolescents predicts smoking initiation (Alexander et al., 1983; Coombs et al., 1986). According to the results from the National Youth Tobacco Survey conducted by the American Legacy Foundation and the Center for Disease Control (ALF, 2001), nearly two-thirds of high school students and one-third of middle school students have tried a puff or more of a cigarette. First experimentation with smoking generally begins in the early part of adolescence, during the transition from elementary school to middle school. During the high school years, rates of smoking onset level off. The peak age group for initiation and experimentation is age 11 through 15 (Alexander et al., 1983; Coombs, Fawzy, & Gerber, 1986). Personaland InterpersonalFactors Risk-Taking In adolescence, deviant behaviors such as risk-taking and rebelliousness have been associated with drug abuse, including cigarette smoking (Jessor&Jessor, 1977; Dinn et al., 2004; Burt et al., 2000). Adolescent tobacco users generally are described as being more rebellious, risk-taking, impulsive and novelty-seeking than are their non-smoking counterparts (Dinn et al., 2004; Barefoot et al., 1989; Lipkus et al., 1994; Simons-Morton et al., 1999; Burt et al., 2000). In addition, Chassin et al. (1989) found that deviance was a significant predictor of cigarette smoking in high school students. Similarly, Turbin and colleagues (2000) found that deviantprone adolescents were more likely to engage in risky behaviors, including smoking. Explanation for this relationship are less clear and may include peer affiliations, sensation seeking, or less concern about negative consequences.
  3. 3. SMOKING: RISK FACTORS AND INTERVENTIONS 3 Self- Esteem The process of identity-formation is central part of adolescent development. An adolescent‟s sense of self-worth develops during the adolescent period and is influenced largely by interaction with peers, parents, and teachers. Therefore, behaviors that bring approval from others are likely to enhance self-esteem and are more likely to be repeated, even if these behaviors are accompanied by some cost to the individual. Several studies, for instance, have reported that individuals with low self-esteem are more likely than individuals with high selfesteem to initiate smoking (Young &Werch, 1990; Botvin et al., 1992; Stacy et al., 1992; Conard et al., 1992). Self-Efficacy Self-efficacy is defined as an individual‟s belief in their ability to reach a desired a goal (Bandura, 1986; Elickson and Hayes, 1990; DeVries et al., 1990). For adolescents, self-efficacy is an important predictor of smoking initiation (Bandura, 1986). Specifically, the less an adolescent feels s/he can resist the pressure to smoke, the more likely s/he will be likely to initiate smoking (Ellickson and Hays, 1990; DeVries et al., 1990). In contrast, higher selfefficacy appears to protect against peer influences to smoke (Conard et al., 1992). Family Parental smoking appears to have the strongest influence for white and female adolescents, especially in the early stages of smoking (Bauman, Foshee, Linzar, & Koch, 1990; Chassin, Presson, Montello, Sherman, & McGrew, 1990; Sussman, Dent, Flay, Hansen, & Johnson, 1987). A review of the literature suggests that this influence may also include other factors, such as parental approval or disapproval of smoking, parental involvement in
  4. 4. SMOKING: RISK FACTORS AND INTERVENTIONS 4 adolescent‟s free-time supervision, the style and extent of parental communication o health related matters and whether or not parents promote academic achievement for their children. Peers Smoking initiation seems to be a part of peer associations and peer bonding in adolescence. Smoking may be a shared behavior that certain groups use to differentiate themselves from other peers and from adults. Adolescents usually try their first cigarette with their peers; peers may then provide expectation, reinforcement and opportunities for continuation. The influence of peers may be particularly strong during the preparatory trying and experimentation stages; during the regular use and addiction stages, personal and pharmalogical factors may become more important. Attitudes/Expectations/Perceptions Although an adolescent‟s general knowledge of the adverse health consequences of smoking is a poor predictor of subsequent use, smoking risks that are personalized and individualized appear to be important. The perceived positive functions of smoking as well as an expected utility of cigarette use are significant predictors (Leventhal& Cleary, 1980; Perry et al., 1987; Bauman, Fisher, Bryan, & Chenoweth, 1984). These factors are related to having a positive social image, bonding with peers, and being “mature”; all are socially relevant for teenagers. Other factors that strongly predict future smoking include intentions to smoke and prior experimentation (Conard et al., 1992). The initial adverse physiological reactions to initial smoking diminish with repeated tries, and tolerance to nicotine increases. Nicotine dependence is associated with a shift from social to more personal, individual reasons for smoking. Rebellious attitude is also the precursor for smoking in adolescence.
  5. 5. SMOKING: RISK FACTORS AND INTERVENTIONS 5 Psychobiological Factors In addition to psychosocial reasons for smoking, adolescents report smoking to obtain its psychological effects. Specifically, adolescents report smoking to reduce anxiety, to control appetite and body weight, to regulate mood states, to improve attention, and for nicotine‟s reinforcing or stimulating actions (Barker et al., 2004). Identification of how these factors contribute to smoking is important because the more an adolescents views smoking as beneficial, the more likely s/he is likely to initiate smoking. Positive reinforcement Nicotine is a psychomotor stimulant that produces positive subjective sensations of reward and these effects are likely to contribute to smoking initiation and maintenance (Ikard et al., 1969; Garrett & Griffiths, 2001). Adult smokers reliably cite the positive stimulating effects of nicotine as reasons for smoking (USDDHS, 1988; Copeland et al., 1995). Further, many adolescents who smoke report that smoking brings pleasurable effects (USDDHS, 1988). Animals‟ models of nicotine exposure have demonstrated stimulating effects of nicotine- actions that reflect dopaminergic stimulation. Body Weight Control Adolescents, especiallyadolescent girls, may be influenced to smoke by their beliefs that smoking affects appetite and body weight. The belief that smoking cigarette curbs weight gain and reduces appetite has been prospectively associated with smoking initiation, particularly among adolescent girls (Austin &Gortmaker, 2001). This expectation is likely based on reports that adult smokers weight less than non-smokers (Grunberg, 1982; Wack & Rodin, 1982; Fisher
  6. 6. SMOKING: RISK FACTORS AND INTERVENTIONS 6 & Gordon, 1985; USDHHS,1988) and that smoking cessation results in weight gain (Grunberg, 1982; USDHHS,1988; Faraday et al., 2003). Addiction Dependence Nicotine dependence is characterized by tolerance, unsuccessful efforts to cut down use, cravings, and continued used despite knowledge of harmful effects (USDHHS, 1988; DSM-IV, 1994). Many adolescents progress to dependence much quicker than do adults, exhibiting signs of nicotine dependence in a few days to weeks after initiation, even before they become regular smokers (Chen & Miller, 1988; Breslau et al., 2001). Other studies shows that girls reported more symptoms than did boys even though they smoked at the same rate. Individuals who begin smoking in adolescence are likely to smoke for a greater number of years and to smoke more heavily as adults. (Ershler et al., 1989; Breslau et al., 1993b; Chen &Millar, 1998). Withdrawal Symptoms of nicotine withdrawal include: dysphoria, depressed mood, frustration, anger, irritability, difficulty concentrating, restlessness, increased appetite, and cravings (USDHHS, 1988; DSM-IV, 1994). Ershler et al., (1989) reported that more than half of adolescents who try to quit smoking experience such withdrawal symptoms. Adolescents reported that the experience of these symptoms is one of the primary reasons why quitting smoking is so difficult (Johnson et al., 1982).in 200, the National Youth Tobacco Survey revealed that among adolescent smokers more than half wanted to smoke and have tried quitting at least once during the past 12 months (Johnson et al., 1982; CDC, 2001). Of the more than 60% of adolescents who report wanting to quit, less than 5% are successful (Burt & Peterson. 1998).
  7. 7. SMOKING: RISK FACTORS AND INTERVENTIONS 7 Psychological Factors Affective Regulation Stress and Anxiety Reduction Psychosocial stress has been associated with smoking in adolescence. Adolescents frequently report that they smoke to cope with stress or to manage negative affect (Mates &Allison, 1992). Koval et al. (2002) evaluated the relationship between stress and smoking among sixth graders and eighth graders and found that for both males and females, increasing levels of stress were associated with increasing levels of smoking. Cheetah et al. (2001) reported that nicotine was anxiolytic (anxiety reducing) at low dosages for adolescent females and at higher dosages for adolescent males. Together these findings suggest that nicotine‟s actions to reduce anxiety in adolescence might differ based on gender and the context in which anxiety occurs. Observation Children and adolescents develop their intentions to smoke and their expectations about smoking prior to every starting. Expectations about the effects of smoking are based largely on observations of other people who smoke. These observations help to shape perceptions about the consequences of smoking behavior and influence of observer‟s intent to smoke or not to smoke. For children and adolescents, role models include parents, elder siblings, relatives, teachers, peers, media representatives or other inspired figures. Smoking has been initiated sometimes only as the result of aspiration which may lead to heavy smoking (Owing, 2012). Cognitive Enhancement Attentional Regulation
  8. 8. SMOKING: RISK FACTORS AND INTERVENTIONS 8 Smokers frequently report smoking to enhance attention. Research with human smokers suggests that smoking does increase attention (Conners et al., 1996). Further, recent research suggests that individuals with attention-deficit/hyperactive disorder (ADHD) use nicotine to enhance attention and/or cognitive performance (Levin et al., 1996). Whereas most adolescents do not report smoking to increase attention, the preponderance of smoking among attentiondisordered youth suggests that attentionalregulation may play a role in why adolescents maintain cigarette smoking (Whalen et al., 2003; Flory &Lynam, 2003). Environmental Risk Factors Socioeconomic Status Socioeconomic status is inversely related to smoking behavior such that low SES is associated with increased smoking behavior (Conard et al., 1992). Conard and his colleagues reviewed twenty-one prospective studies on the relationship between parental SES and adolescent smoking. Of these studies, 76% supported the inverse relationship between low SES and greater smoking rates. While it is possible that difference in exposure to health promoting resources explain this relationship, another intriguing explanation exists. Media When media glamorize smoking, portray smoking as an effective way to reduce stress, associate tobacco use with sexual activities, make it appear attractive by displaying these themes on highly influencing public figures including professional athletes, musicians and actors; adolescents attitude towards smoking are greatly affected. Unfortunately, tobacco use in the media does not accurately reflects rates of smoking in the general population and generally does not reveal the health hazards that result from tobacco use. Tobacco use in the television and movies occurs at much higher rates than do smoking rates among the general population (Hazen
  9. 9. SMOKING: RISK FACTORS AND INTERVENTIONS et al., 1977; Glantz, 2003; 2004; Stockwell & Glantz, 1994). Therefore media creates an unrealistic representation of smoking behavior for impressionable youth and presents only positive impression of this deadly behavior. Advertisements and Promotion In 1990, cigarette companies spent almost 4 billion dollars on advertising and promotional activities (Federal Trade Commission, 1992). These ample expenditures made cigarettes the second most promoted consumer product (after automobiles) in the United States. The tobacco industry claimsthat the purpose of advertising is to increase brand switiching and to increase market shares of adult consumers.Yet, the evidence shows that some young people are recruited to smoking by brand advertising. The assertion is supported by data showing that adolescents consistently smoke the most heavily advertised brands of cigarettes ( McCarthy & Gritz, 1984; Baker, Hmel, Flaherty & Trebilco, 1987; DiFranza et al., 1991). 9
  10. 10. SMOKING: RISK FACTORS AND INTERVENTIONS 10 Interventions for Smoking Cessation Interventions to promote cessation can be described as clinical interventions which are aimed at the individual, self-help movements and public health interventions, which are aimed at populations. Clinical interventions: promoting individual change Clinical interventions often take the form of group or individual treatment programs based in hospitals or universities requiring regular attendance over a 6- or 12-week period. These interventions use a combination of approaches that reflect the different disease and social learning theory models of addiction and are provided for those individuals who seek help. Aversion therapies It aims to punish smoking rather than rewarding it. Imaginal aversion techniques have been used for smokers and encourage the smoker to imagine the negative consequence of smoking, such as being sick (rather than actually experiencing them). However, imaginal techniques seem to add nothing to other behavioral treatments (Lichtenstein and Brown 1983). Rapid smoking is a more successful form of aversion therapy (Danaher 1977) and aims to make the actual process of smoking unpleasant. Smokers are required to sit in a closed room and take a puff every six seconds until it becomes so unpleasant they cannot smoke any more. Although there is some evidence to support rapid smoking as a smoking-cessation technique, it has obvious side effects, including increased blood carbon monoxide levels and heart rates. Other aversion therapies include focused smoking, which involves smokers concentrating on all the negative experiences of smoking, and smoke-holding, which involves smokers holding smoke in their mouths for a period of time and again thinking about the unpleasant sensations. Smoke-
  11. 11. SMOKING: RISK FACTORS AND INTERVENTIONS 11 holding has been shown to be more successful at promoting cessation than focused smoking and it does not have the side effects of rapid smoking (Walker and Franzini 1985). Contingency contracting Contingency contractingprocedures also aim to punish smoking and to reward abstinence. Smokers are asked to make a contract with a therapist, a friend or partner and to establish a set of rewards/punishments, which are contingent on their smoking/drinking cessation. For example, money may be deposited with the therapist and only returned when they have stopped smoking/drinking for a given period of time. They are therefore rewarding abstinence. Schwartz (1987) analyzed a series of contingency contracting studies for smoking cessation and concluded that this procedure seems to be successful in promoting initial cessation but once the contract was finished, or the money returned, relapse was high. However, whether such changes in behavior would persist over time is unclear. In addition, this perspective is reminiscent of a more punitive moral model of addictions. Cue exposure procedures It focuses on the environmental factors that have become associated with smoking. For example, if an individual always smokes when they drink alcohol, alcohol will become a strong external cue to smoke. Cue exposure techniques gradually expose the individual to different cues and encourage them to develop coping strategies to deal with them. This procedure aims to extinguish the response to the cues over time and is opposite to cue avoidance procedures, which encourage individuals not to go to the places where they may feel the urge to smoke. Self-management procedures It uses a variety of behavioral techniques to promote smoking cessation in individuals and may be carried out under professional guidance. Such procedures involve self-monitoring
  12. 12. SMOKING: RISK FACTORS AND INTERVENTIONS 12 (keeping a record of own smoking behavior), becoming aware of the causes of smoking (What makes me smoke? Where do I smoke?), and becoming aware of the consequences of smoking (Does it make me feel better? What do I expect from smoking?). However, used on their own, self-management techniques do not appear to be more successful than other interventions (Hall et al. 1990). Multi-perspective cessation clinics It represents an integration of all the above clinical approaches to smoking cessation and use a combination of aversion therapies, contingency contracting, cue exposure and selfmanagement. In addition, for smoking cessation this multi-perspective approach often incorporates disease model-based interventions such as nicotine replacement. Lando (1977) developed an integrated model of smoking cessation, which has served as a model for subsequent clinics. Lando‟s model has been evaluated and research suggested a 76 per cent abstinence rate at 6 months (Lando 1977) and 46 per cent at 12 months (Lando and McGovern 1982), which was higher than the control group‟s abstinence rates. Killen et al. (1984) developed Lando‟s approach but used smoke-holding rather than rapid smoking, and added nicotine chewing gum into the program. Their results showed similarly high abstinence rates to the study by Lando. Self-help movements Although clinical and public health interventions have proliferated over the past few decades, up to 90 per cent of ex-smokers report having stopped without any formal help (Fiore et al. 1990). Lichtenstein and Glasgow (1992) reviewed the literature on self-help quitting and reported that success rates tend to be about 10–20 per cent at one-year follow-up and 3–5 percent for continued cessation. The literature suggests that lighter smokers are more likely to be
  13. 13. SMOKING: RISK FACTORS AND INTERVENTIONS 13 successful at self-quitting than heavy smokers and those minimal interventions, such as follow up telephone calls, can improve this success. Research also suggests that smokers are more likely to quit if they receive support from their partners and if their partners also stop smoking (Cohen and Lichtenstein 1990) and that partner support is particularly relevant for women trying to give up smoking during pregnancy (e.g. Appleton and Pharoah 1998). However, although many exsmokers report that „I did it on my own‟, it is important not to discount their exposure to the multitude of health education messages received via television, radio or leaflets. Public Health Interventions: Promoting Cessation in Populations Public health interventions aim to promote behavior change in populations and have become increasingly popular over recent years. Such interventions are aimed at all individuals, not just those who seek help. Doctor’s advice Approximately 70 per cent of smokers will visit a doctor at some time each year. Research suggests that the recommendation from a doctor, who is considered a credible source of information, can be quite successful in promoting smoking cessation. Research also suggests that the effectiveness of doctors‟ advice may be increased if they are trained in patient-centered counseling techniques (Wilson et al. 1988). School Interventions In some regions of the world, school interventions are considered as integral part for smoking cessation. But it has been observed that the positive effects of even the most successful prevention programs tend to diminish over time (Flay et el., 1989). This has been particularly noted among school based intervention studies that included little emphasis on booster sessions, few communitywide activities or few mass media components (Botvin&Botvin, 1992).
  14. 14. SMOKING: RISK FACTORS AND INTERVENTIONS 14 The National Cancer Institute convened a panel of experts in 1987 to reach consensus on the essential elements of school based smoking-prevention programs (USDHHS, 1991). These included classroom sessions to be delivered at least five times per year in each of two years in the sixth through eighth grades, emphasis on social factors that influence smoking onset, its short term consequences and refusal skills. Incorporation of the program into the existing school curricula, during the transition from elementary school to junior high or middle school and involvement of students in the presentation and delivery of the program. The intervention also comprised of encouragement of parental involvement, adequate training of the teachers and social and cultural acceptance of the program in each community. Worksite interventions Over the past decade there has been an increasing interest in developing worksite-based smoking-cessation interventions. These take the form of either a company adopting a nosmoking policy and/or establishing work-based health promotion programs. In addition, the large number of people involved presents the opportunity for group motivation and social support. Furthermore, they may have implications for reducing passive smoking at work, which may be a risk factor for coronary heart disease (He et al. 1994). In two Australian studies, public service workers were surveyed following smoking bans in 44 government office buildings about their attitudes to the ban immediately after the ban and after six months. The results suggested that although immediately after the ban many smokers felt inconvenient, these attitudes improved at six months with both smokers and non-smokers recognizing the benefits of the ban. However, only 2 per cent stopped smoking during this period (Borland et al. 1990).
  15. 15. SMOKING: RISK FACTORS AND INTERVENTIONS 15 Community-based programs Large community-based programs have been established as a means of promoting smoking cessation within large groups of individuals. Such programs aim to reach those who would not attend clinics and to use the group motivation and social support in a similar way to worksite interventions. In the Stanford Five City Project, the experimental groups received intensive face-to-face instruction on how to stop smoking and in addition were exposed to media information regarding smoking cessation. The results showed a 13 per cent reduction in smoking rates compared with the control group (Farquhar et al. 1990). In the North Karelia Project, individuals in the target community received an intensive educational campaign and were compared with those in a neighboring community who were not exposed to the campaign. The results from this program showed a 10 per cent reduction in smoking in men in North Karelia compared with men in the control region. In addition, the results also showed a 24 per cent decline in cardiovascular deaths, a rate twice that of the rest of the country (Puska et al. 1985). Government interventions An additional means to promote smoking cessation is to encourage governments to intervene. Such interventions can take several forms Restricting/banning advertising According to social learning theory, individual learn to smoke by associating it with attractive characteristics, such as „It will help me relax‟, „It makes me look sophisticated‟, „It makes me look sexy‟, „It is risky‟. Advertising aims to access and promote these beliefs in order to encourage smoking. Implementing a ban/restriction on advertising would remove this source of beliefs. In the UK, cigarette advertising was banned in 2003.
  16. 16. SMOKING: RISK FACTORS AND INTERVENTIONS 16 Increasing the cost Research indicates a relationship between the cost of cigarettes and their consumption. Increasing the price of cigarettes could promote smoking cessation and deter the initiation of these behaviors, particularly among children. According to models of health beliefs, this would contribute to the perceived costs of the behaviors and the perceived benefits of behavior change. Banning smoking in public places Smoking is already restricted to specific places in many countries (e.g. in the UK most public transport is no smoking). A wider ban on smoking may promote smoking cessation. According to social learning theory, this would result in the cues to smoking (e.g. restaurants, bars) becoming eventually disassociated from smoking. However, it is possible that this would simply result in compensatory smoking in other places as illustrated by some of the research on worksite no-smoking policies. To date, smoking has been banned in public places in Ireland, Scotland, several states in the US, much of Italy and banned in England from July 2007. Banning cigarette smoking Governments could opt to ban cigarettes completely (although they would forego the large revenues they currently receive from advertising and sales). Such a move might result in a reduction in these behaviors. In fact the smoking bans in Ireland and in some states in the USA have resulted in a range of positive outcomes such as a reduction in smoking per se and even a decline in patients admitted to hospital for heart attacks.
  17. 17. SMOKING: RISK FACTORS AND INTERVENTIONS 17 References J. H. Owing. (2005). Trends in Smoking and Health Research. [Nova Publisher]. Retrieved from http://books.google.com.pk/books?id=Y5n32SOUJmwC&pg=PA148&dq=factors+influe ncing+smoking&hl=en&sa=X&ei=bNGsUJeWG4Gf0QX2poDwDg&ved=0CDEQ6AE wAg#v=onepage&q=factors%20influencing%20smoking&f=false J. Odgen. (2007). Health Psychology: A text Book. [McGraw Hill International]. Retrieved from http://books.google.com.pk/books/about/Health_Psychology.html?id=2d0RXtUwyTIC&r edir_esc=y L. J. Haas. (2004). Handbook of Primary Care Psychology.[Oxford University Press]. Retrieved from http://books.google.com.pk/books?id=vVlM6CHT_gC&pg=PR4&dq=Handbook+of+Pri mary+Care+Psychology++edited+by+Leonard+J.+Haas&hl=en&sa=X&ei=4Z7UJ_IM8f EswbB3oGoAg&redir_esc=y M. Feuerstein., E. E. Labbé., & A. R. Kuczmierczyk. (1986). Health Psychology: A Psychobiological Perspective. [Springer]. Retrieved from http://books.google.com.pk/books?id=GMioZq2l2DEC&printsec=frontcover&dq=Health +Psychology:+A+Psychobiological+Perspective.&hl=en&sa=X&ei=_qC7UO3sGIrLswa EzoD4BA&redir_esc=y R. Goldberg. (2009). Drugs Across the Spectrum. [Cengage]. Retrieved from http://books.google.com.pk/books?id=xQ0aj0sxJNUC&pg=PA319&dq=psychosocial+fa ctors+influencing+smoking&hl=en&sa=X&ei=6ZGvUK_DAou3hAeXiYHYDg&ved=0 CEkQ6AEwCQ#v=onepage&q=psychosocial%20factors%20influencing%20smoking&f =false
  18. 18. SMOKING: RISK FACTORS AND INTERVENTIONS 18 R. J. DiClemente., W. B. Hansen., & L .E. Ponton. (1995). Handbook of Adolescent Health Risk Behavior: Health Risk Behavior. [Springer]. Retrieved from http://books.google.com.pk/books?id=DoSU8Xo_ahQC&pg=PA61&dq=psychosocial+fa ctors+influencing+smoking&hl=en&sa=X&ei=6ZGvUK_DAou3hAeXiYHYDg&ved=0 CEMQ6AEwBw#v=onepage&q=psychosocial%20factors%20influencing%20smoking& f=false

×