Introduction to Patient Safety ResearchIntroduction to Patient Safety Research
Presentation 9 - Understanding Causes: Coho...
2: Introduction: Study Details
 Full ReferenceFull Reference
Cullen DJ, Sweitzer BJ, Bates DW, Burdick E, Edmondson A, Le...
3: Introduction: Research Team
 Head researcher – David J. Cullen, MD, MSHead researcher – David J. Cullen, MD, MS
Former...
4: Background: Opening Points
 Medical treatment is estimated to accidentally injure 1.3 millionMedical treatment is esti...
5: Background: Study Rationale
 Many adverse drug events (ADEs) are preventableMany adverse drug events (ADEs) are preven...
6: Background: Setting Up a Research Team
 Part of a larger study of adverse drug eventsPart of a larger study of adverse...
7: Methods: Study Design
 DesignDesign: prospective cohort study: prospective cohort study
 ObjectivesObjectives::
 To ...
8: Study Design: Population and Setting
 PopulationPopulation: 4,031 adult patients admitted to 11 ICU and general: 4,031...
9: Methods: Data Collection
 Incidents wereIncidents were identifiedidentified in three ways:in three ways:
 Unit person...
10: Methods: Data Collection (2)
 Each preventable or potential ADEEach preventable or potential ADE investigatedinvestig...
11: Methods: Interviews
 Case-investigators used structured forms to seek details aboutCase-investigators used structured...
12: Methods: Data Analysis and Interpretation
 Results of each preventable ADE analyzed by a multidisciplinaryResults of ...
13: Results: Key Findings
 Study identified 247 adverse drug events in 206 admissionsStudy identified 247 adverse drug ev...
14: Results: Key Findings (2)
 Medical ICU rate (25 events per 1000 patient days) wasMedical ICU rate (25 events per 1000...
15: Conclusion: Main Points
 Unadjusted rate of preventable and potential adverse drugUnadjusted rate of preventable and ...
16: Conclusion: Discussion
 Reducing the number of drugs used in the ICU may decrease theReducing the number of drugs use...
17: Conclusion: Discussion (2)
 Study limitationsStudy limitations
 Study included only two tertiary care hospitals that...
18: Conclusion: Study Impact
 Academic impactAcademic impact
 More than 20 major articles published in leading general m...
19: Conclusion: Study Impact (2)
 Policy impactPolicy impact
 Increased awareness of medical errors and the need to fixI...
20: Conclusion: Practical Considerations
 Study durationStudy duration
 60 months from conception to write-up60 months f...
21: Author Reflections: Overcoming Barriers
 Need for informed consent?Need for informed consent?
 "The Human Studies Co...
22: Author Reflections: Lessons and Advice
 If you could do one thing differently in this study what would itIf you could...
23: Author Reflections: Ideas for Future Research
 What message do you have for future researchers fromWhat message do yo...
24: Additional References and Resources
 InstitutionsInstitutions
 National Patient Safety FoundationNational Patient Sa...
Upcoming SlideShare
Loading in …5
×

Introduction to Patient Safety Research

455 views

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
455
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
8
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Introduction to Patient Safety Research

  1. 1. Introduction to Patient Safety ResearchIntroduction to Patient Safety Research Presentation 9 - Understanding Causes: Cohort StudyPresentation 9 - Understanding Causes: Cohort Study
  2. 2. 2: Introduction: Study Details  Full ReferenceFull Reference Cullen DJ, Sweitzer BJ, Bates DW, Burdick E, Edmondson A, LeapeCullen DJ, Sweitzer BJ, Bates DW, Burdick E, Edmondson A, Leape LL. Preventable adverse drug events in hospitalized patients: aLL. Preventable adverse drug events in hospitalized patients: a comparative study of intensive care and general care units. Critcomparative study of intensive care and general care units. Crit Care Med, 1997, 25;1289-1297Care Med, 1997, 25;1289-1297 Link to Abstract (HTML)Link to Abstract (HTML) Link to Full TextLink to Full Text Can be ordered online at:Can be ordered online at: http://www.ccmjournal.comhttp://www.ccmjournal.com
  3. 3. 3: Introduction: Research Team  Head researcher – David J. Cullen, MD, MSHead researcher – David J. Cullen, MD, MS Former Chairman of Department of Anaesthesiology and PainFormer Chairman of Department of Anaesthesiology and Pain Medicine (1996 – 2005)Medicine (1996 – 2005) St. Elizabeth's Medical Center and Tufts University Medical School inSt. Elizabeth's Medical Center and Tufts University Medical School in Boston, Massachusetts, USABoston, Massachusetts, USA Areas of expertise: anaesthesiology and critical care medicineAreas of expertise: anaesthesiology and critical care medicine  Other team members:Other team members: Bobbie Jean Sweitzer, MDBobbie Jean Sweitzer, MD David W. Bates, MDDavid W. Bates, MD Elisabeth Burdick, MSElisabeth Burdick, MS Amy Edmondson, PhDAmy Edmondson, PhD Lucian Leape, MDLucian Leape, MD
  4. 4. 4: Background: Opening Points  Medical treatment is estimated to accidentally injure 1.3 millionMedical treatment is estimated to accidentally injure 1.3 million people each year in the USpeople each year in the US  Harvard Medical Practice Study found that medications are the mostHarvard Medical Practice Study found that medications are the most common cause of adverse eventscommon cause of adverse events  Patients in intensive care units (ICUs) are at especially high riskPatients in intensive care units (ICUs) are at especially high risk of an adverse drug event related to human error because:of an adverse drug event related to human error because:  Workload is intenseWorkload is intense  Many interactions between patients and caregiversMany interactions between patients and caregivers  Critical illness reduces both the patients' natural resilience andCritical illness reduces both the patients' natural resilience and ability to defend themselves from consequences of human errorability to defend themselves from consequences of human error  Patients in the ICU receive twice as many drugs as patients inPatients in the ICU receive twice as many drugs as patients in general care unitsgeneral care units
  5. 5. 5: Background: Study Rationale  Many adverse drug events (ADEs) are preventableMany adverse drug events (ADEs) are preventable  Understanding how errors in drug use occur is essential forUnderstanding how errors in drug use occur is essential for reducing injuries and developing prevention strategiesreducing injuries and developing prevention strategies  "Our intent was to study human errors leading to ADEs, looking for"Our intent was to study human errors leading to ADEs, looking for systemic problems and designing system wide solutions and thensystemic problems and designing system wide solutions and then testing their efficacy."testing their efficacy."
  6. 6. 6: Background: Setting Up a Research Team  Part of a larger study of adverse drug eventsPart of a larger study of adverse drug events  Selecting collaborators:Selecting collaborators:  ""Those whom I chose were based on interest, motivation andThose whom I chose were based on interest, motivation and ambition."ambition."  Obtaining funding:Obtaining funding:  Federal Grant from US Agency for Health Care Policy and ResearchFederal Grant from US Agency for Health Care Policy and Research  Smaller grants obtained from Harvard malpractice insurerSmaller grants obtained from Harvard malpractice insurer
  7. 7. 7: Methods: Study Design  DesignDesign: prospective cohort study: prospective cohort study  ObjectivesObjectives::  To compare the frequency and preventability of adverse drugTo compare the frequency and preventability of adverse drug events and potential adverse drug events in ICUs and non-ICUsevents and potential adverse drug events in ICUs and non-ICUs  To evaluate systems factors involving the individual caregivers, careTo evaluate systems factors involving the individual caregivers, care unit teams, and patients involved in each adverse drug event byunit teams, and patients involved in each adverse drug event by comparing:comparing: • ICUs with non-ICUsICUs with non-ICUs • Medical ICUs with surgical ICUsMedical ICUs with surgical ICUs
  8. 8. 8: Study Design: Population and Setting  PopulationPopulation: 4,031 adult patients admitted to 11 ICU and general: 4,031 adult patients admitted to 11 ICU and general care units in two tertiary care hospitals in the US between Feb.care units in two tertiary care hospitals in the US between Feb. and July 1993and July 1993  Two medical ICUsTwo medical ICUs  Three surgical ICUsThree surgical ICUs  Four medical general care unitsFour medical general care units  Two surgical general care unitsTwo surgical general care units  SamplingSampling: Stratified, random sample of patients admitted to: Stratified, random sample of patients admitted to medical and surgical unitsmedical and surgical units  Patients eligible to be in study more than oncePatients eligible to be in study more than once  When patients had more then one adverse drug event, only the firstWhen patients had more then one adverse drug event, only the first episode in that admission was evaluatedepisode in that admission was evaluated
  9. 9. 9: Methods: Data Collection  Incidents wereIncidents were identifiedidentified in three ways:in three ways:  Unit personnel asked to report incidents to nurse investigatorsUnit personnel asked to report incidents to nurse investigators  Nurse investigator visited each unit and solicited information fromNurse investigator visited each unit and solicited information from nurses, pharmacists, and clerical personnel concerning all actual ornurses, pharmacists, and clerical personnel concerning all actual or potential drug-related incidentspotential drug-related incidents  Nurse investigator reviewed all charts daily on weekdays and onceNurse investigator reviewed all charts daily on weekdays and once on weekendson weekends  All incidents evaluated independently by two physicianAll incidents evaluated independently by two physician reviewers andreviewers and classifiedclassified according to:according to:  Whether they represented actual or potential ADEsWhether they represented actual or potential ADEs  Severity and preventability of the eventSeverity and preventability of the event
  10. 10. 10: Methods: Data Collection (2)  Each preventable or potential ADEEach preventable or potential ADE investigatedinvestigated to determine ifto determine if there was an error and if so, the circumstances, apparentthere was an error and if so, the circumstances, apparent causes, and profiles of the persons involvedcauses, and profiles of the persons involved  Individuals involved in the preventable actual or potential ADEIndividuals involved in the preventable actual or potential ADE underwent detailed interviewsunderwent detailed interviews  Interviews conducted by peer case-investigators (physician toInterviews conducted by peer case-investigators (physician to physician, nurse to nurse, and pharmacist to pharmacist)physician, nurse to nurse, and pharmacist to pharmacist)
  11. 11. 11: Methods: Interviews  Case-investigators used structured forms to seek details aboutCase-investigators used structured forms to seek details about the circumstances surrounding the incidentthe circumstances surrounding the incident  E.g.experience with the drug, treatment plan, stress factors,E.g.experience with the drug, treatment plan, stress factors, external distractions, sleep deprivation, etc.external distractions, sleep deprivation, etc.  Interviewees were asked to self-assess:Interviewees were asked to self-assess:  Competency and skillCompetency and skill  Decision-making styleDecision-making style  Openness to changeOpenness to change  Duration on the service or jobDuration on the service or job  Amount and quality of supervisionAmount and quality of supervision  Relationship of the incident to the timing of their shiftRelationship of the incident to the timing of their shift  Respondents asked to discuss their perception of why the eventRespondents asked to discuss their perception of why the event occurred, graded on a 1 to 5 Likert scaleoccurred, graded on a 1 to 5 Likert scale
  12. 12. 12: Methods: Data Analysis and Interpretation  Results of each preventable ADE analyzed by a multidisciplinaryResults of each preventable ADE analyzed by a multidisciplinary team of physicians, pharmacists, nurses and systems analyststeam of physicians, pharmacists, nurses and systems analysts  Analyses performed:Analyses performed:  Comparison of difference between units in rates of adverse drugComparison of difference between units in rates of adverse drug events (Chi-square, analysis of variance, and unpaired t-tests)events (Chi-square, analysis of variance, and unpaired t-tests)  Univariate comparison of resource utilization (Wilcoxon rank-sumUnivariate comparison of resource utilization (Wilcoxon rank-sum test)test)  Multivariate comparisons of post-event length of stay and resourceMultivariate comparisons of post-event length of stay and resource utilization for ICU vs. non-ICU patients and medical vs. surgicalutilization for ICU vs. non-ICU patients and medical vs. surgical patients (multiple linear regression)patients (multiple linear regression)
  13. 13. 13: Results: Key Findings  Study identified 247 adverse drug events in 206 admissionsStudy identified 247 adverse drug events in 206 admissions  236 persons involved in the preventable and potential ADEs236 persons involved in the preventable and potential ADEs interviewed by a peer case-investigatorinterviewed by a peer case-investigator  Rate of preventable ADEs and potential ADEs in ICUs was 19Rate of preventable ADEs and potential ADEs in ICUs was 19 events per 1000 patient days: nearly twice the rate for non-ICUsevents per 1000 patient days: nearly twice the rate for non-ICUs (10)(10)  However, when adjusted for the number of drugs used, noHowever, when adjusted for the number of drugs used, no statistically significant differences in rates between ICUs andstatistically significant differences in rates between ICUs and non-ICUsnon-ICUs
  14. 14. 14: Results: Key Findings (2)  Medical ICU rate (25 events per 1000 patient days) wasMedical ICU rate (25 events per 1000 patient days) was significantly higher than the surgical ICU rate (14 events persignificantly higher than the surgical ICU rate (14 events per 1000 patient days)1000 patient days)  Length of stay and severity of the adverse drug event wereLength of stay and severity of the adverse drug event were greater in ICUs than non-ICUs, but there were no differencesgreater in ICUs than non-ICUs, but there were no differences between medical ICU and surgical ICU patientsbetween medical ICU and surgical ICU patients  Structured interviews indicated almost no differences betweenStructured interviews indicated almost no differences between ICUs and non-ICUs for many characteristics of the patient,ICUs and non-ICUs for many characteristics of the patient, patient care team, systems, and individual caregivers.patient care team, systems, and individual caregivers.
  15. 15. 15: Conclusion: Main Points  Unadjusted rate of preventable and potential adverse drugUnadjusted rate of preventable and potential adverse drug events was twice as high in ICUs compared with non-ICUsevents was twice as high in ICUs compared with non-ICUs  However, when adjusted for the number of drugs ordered,However, when adjusted for the number of drugs ordered, there was no greater likelihood for preventable ADEs andthere was no greater likelihood for preventable ADEs and potential ADEs to occur in ICUs than in non-ICUspotential ADEs to occur in ICUs than in non-ICUs  Preventable adverse drug events and potential adverse drugPreventable adverse drug events and potential adverse drug events occurred in units that functioned normallyevents occurred in units that functioned normally  Involved caregivers who were working under normal circumstances,Involved caregivers who were working under normal circumstances, not at the extremes of workload, stress, or a difficult environmentnot at the extremes of workload, stress, or a difficult environment
  16. 16. 16: Conclusion: Discussion  Reducing the number of drugs used in the ICU may decrease theReducing the number of drugs used in the ICU may decrease the incidence of adverse drug eventsincidence of adverse drug events  Even if only a small fraction of errors result in injury, this rate canEven if only a small fraction of errors result in injury, this rate can be substantial in the ICU because of the intensity of treatmentbe substantial in the ICU because of the intensity of treatment  Systems failures may be far more important contributing factorsSystems failures may be far more important contributing factors to ADEs than the obvious causes of fatigue and stressto ADEs than the obvious causes of fatigue and stress  Study did not confirm conventional wisdom that serious errors areStudy did not confirm conventional wisdom that serious errors are made primarily by overworked and exhausted individuals workingmade primarily by overworked and exhausted individuals working with complex patients in an environment filled with distractionswith complex patients in an environment filled with distractions  Common systems failures include poor communication, lack ofCommon systems failures include poor communication, lack of standardization and insufficient labellingstandardization and insufficient labelling
  17. 17. 17: Conclusion: Discussion (2)  Study limitationsStudy limitations  Study included only two tertiary care hospitals that managedStudy included only two tertiary care hospitals that managed relatively similar patientsrelatively similar patients  Methods for detecting ADEs undoubtedly missed some of theseMethods for detecting ADEs undoubtedly missed some of these events – may result in underestimation of incidence of ADEsevents – may result in underestimation of incidence of ADEs  Interviewers could not be blinded to the purposes of the studies –Interviewers could not be blinded to the purposes of the studies – may have introduced interview biasmay have introduced interview bias  Interviewees self-assessment of sleep status may haveInterviewees self-assessment of sleep status may have underestimated degree of fatigueunderestimated degree of fatigue
  18. 18. 18: Conclusion: Study Impact  Academic impactAcademic impact  More than 20 major articles published in leading general medical,More than 20 major articles published in leading general medical, critical care and anaesthesiology journalscritical care and anaesthesiology journals  Extensive citations, lay and professional press media interviewsExtensive citations, lay and professional press media interviews  Practice impactPractice impact  Promoted the development of a patient safety culture based onPromoted the development of a patient safety culture based on scientific studies, not subjective opinionscientific studies, not subjective opinion  Highlighted the important role that clinical pharmacists may play inHighlighted the important role that clinical pharmacists may play in reducing ADEsreducing ADEs
  19. 19. 19: Conclusion: Study Impact (2)  Policy impactPolicy impact  Increased awareness of medical errors and the need to fixIncreased awareness of medical errors and the need to fix problems, not fire peopleproblems, not fire people  Highlighted potential for cost savings through reducing errorsHighlighted potential for cost savings through reducing errors  Led to the formation of the National Patient Safety FoundationLed to the formation of the National Patient Safety Foundation  Patient impactPatient impact  Led to studies of ADEs in the outpatient settings and of comparableLed to studies of ADEs in the outpatient settings and of comparable human errors in medicine (e.g. blood banks)human errors in medicine (e.g. blood banks)
  20. 20. 20: Conclusion: Practical Considerations  Study durationStudy duration  60 months from conception to write-up60 months from conception to write-up  CostCost  Over $1 million USD for the whole study effort (not just this paper)Over $1 million USD for the whole study effort (not just this paper)  Competencies neededCompetencies needed  High level statistician supportHigh level statistician support  Extensive data managementExtensive data management  Expertise from multiple disciplines: psychology, pharmacy, etc.Expertise from multiple disciplines: psychology, pharmacy, etc.  Ethical approvalEthical approval  Took several months to obtain, and some difficulties wereTook several months to obtain, and some difficulties were encountered at one of the two hospitalsencountered at one of the two hospitals
  21. 21. 21: Author Reflections: Overcoming Barriers  Need for informed consent?Need for informed consent?  "The Human Studies Committee wanted informed consent from"The Human Studies Committee wanted informed consent from each patient, even through we never interacted with any patient.each patient, even through we never interacted with any patient. However, we eventually convinced them to back off."However, we eventually convinced them to back off."  Reassuring participants about confidentiality:Reassuring participants about confidentiality:  "Also, those who made the errors were scared to talk privately"Also, those who made the errors were scared to talk privately about it with our interviewers. We had to reassure them about theabout it with our interviewers. We had to reassure them about the confidentiality issues and it worked most of the time."confidentiality issues and it worked most of the time."
  22. 22. 22: Author Reflections: Lessons and Advice  If you could do one thing differently in this study what would itIf you could do one thing differently in this study what would it be?be?  "If we had the resources, study many more hospitals of different"If we had the resources, study many more hospitals of different types, cultures and locations to show generalizability."types, cultures and locations to show generalizability."  Would this research be feasible and applicable in developingWould this research be feasible and applicable in developing countries?countries?  "No, far too many resources needed.""No, far too many resources needed."
  23. 23. 23: Author Reflections: Ideas for Future Research  What message do you have for future researchers fromWhat message do you have for future researchers from developing countries?developing countries?  "Focus on a clear question and don’t try to do too much in any one"Focus on a clear question and don’t try to do too much in any one study."study."  What would be an important research project you recommendWhat would be an important research project you recommend that they do?that they do?  "Test a suggested solution to one human error problem and see if"Test a suggested solution to one human error problem and see if it reduces the specific error."it reduces the specific error."
  24. 24. 24: Additional References and Resources  InstitutionsInstitutions  National Patient Safety FoundationNational Patient Safety Foundation  Lucian Leape FoundationLucian Leape Foundation  ReferencesReferences  Kohn LT, Corrigan JM, Donalson MS, eds. To Err Is Human. InstituteKohn LT, Corrigan JM, Donalson MS, eds. To Err Is Human. Institute of Medicine, Washington, DC: National Academy Press; 1999.of Medicine, Washington, DC: National Academy Press; 1999.  Cullen DJ, Bates DW, Leape LL, and the Adverse Drug EventCullen DJ, Bates DW, Leape LL, and the Adverse Drug Event Prevention Study Group. Prevention of adverse drug events: aPrevention Study Group. Prevention of adverse drug events: a decade of progress in patient safety. J Clin Anesth. 2000;12:600-decade of progress in patient safety. J Clin Anesth. 2000;12:600- 614.614.

×