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Prevention of adverse drug events in hospitals

Junya Zhu, PhD, MS, MA
Saul N Weingart, MD, PhD
Section Editor
Andrew D Auerbach, MD, MPH
Deputy Editor
Judith A Melin, MA, MD, FACP


Adverse drug events (ADEs) comprise the largest single category of adverse events experienced by hospitalized patients, accounting for about 19 percent of all injuries [1]. The occurrence of ADEs is associated with increased morbidity and mortality [2,3], prolonged hospitalizations [4], and higher costs of care [2,5].

A 2007 report from the Institute of Medicine estimated that between 380,000 and 450,000 preventable ADEs occurred annually in United States (US) hospitals [6]. Assuming 400,000 preventable ADEs each year at an incremental hospital cost of $5857 each [5], the estimated cost of ADEs in 2006 was 3.5 billion US dollars [6]. The Joint Commission has established national patient safety goals requiring each health care organization to implement comprehensive medication reconciliation at every transition point (eg, admission, transfer, discharge) along the continuum of care [7].

This topic will focus on interventions to prevent ADEs caused by medication errors in the hospital setting. Specific issues related to hospital discharge, drug prescribing in older adults, and adverse drug reactions (ADRs) are discussed in detail elsewhere. (See "Hospital discharge and readmission" and "Drug prescribing for older adults" and "Drug allergy: Classification and clinical features", section on 'Categories of adverse drug reactions'.)


Adverse drug events (ADEs) are defined as any injuries resulting from medication use, including physical harm, mental harm, or loss of function [8]. ADEs, compared with medication errors, are a more direct measure of patient harm.

Medication errors refer to any mistakes occurring in the medication use process, regardless of whether an injury occurred or whether the potential for injury was present [8,9]. Approximately 1 in 100 medication errors result in an ADE, while 7 in 100 have the potential to do so [10]. Although relatively few medication errors result in ADEs, they provide important information for identifying opportunities to improve patient care.

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Literature review current through: Nov 2017. | This topic last updated: Oct 19, 2017.
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  1. Leape LL, Brennan TA, Laird N, et al. The nature of adverse events in hospitalized patients. Results of the Harvard Medical Practice Study II. N Engl J Med 1991; 324:377.
  2. Classen DC, Pestotnik SL, Evans RS, et al. Adverse drug events in hospitalized patients. Excess length of stay, extra costs, and attributable mortality. JAMA 1997; 277:301.
  3. Phillips DP, Christenfeld N, Glynn LM. Increase in US medication-error deaths between 1983 and 1993. Lancet 1998; 351:643.
  4. Fanikos J, Cina JL, Baroletti S, et al. Adverse drug events in hospitalized cardiac patients. Am J Cardiol 2007; 100:1465.
  5. Bates DW, Spell N, Cullen DJ, et al. The costs of adverse drug events in hospitalized patients. Adverse Drug Events Prevention Study Group. JAMA 1997; 277:307.
  6. Aspden P, Wolcott JA, Bootman JL, Cronenwett LR. Preventing Medication Errors: Quality Chasm Series, The National Academic Press, Washington, DC 2007.
  7. National Patient Safety Goal on Reconciling Medication Information (NPSF.3.06.01). The Joint Commission, 2017. Available at: https://www.jointcommission.org/assets/1/6/NPSG_Chapter_HAP_Jan2017.pdf (Accessed on October 18, 2017).
  8. Bates DW, Cullen DJ, Laird N, et al. Incidence of adverse drug events and potential adverse drug events. Implications for prevention. ADE Prevention Study Group. JAMA 1995; 274:29.
  9. Wittich CM, Burkle CM, Lanier WL. Medication errors: an overview for clinicians. Mayo Clin Proc 2014; 89:1116.
  10. Bates DW, Boyle DL, Vander Vliet MB, et al. Relationship between medication errors and adverse drug events. J Gen Intern Med 1995; 10:199.
  11. Gandhi TK, Seger DL, Bates DW. Identifying drug safety issues: from research to practice. Int J Qual Health Care 2000; 12:69.
  12. Cano FG, Rozenfeld S. Adverse drug events in hospitals: a systematic review. Cad Saude Publica 2009; 25 Suppl 3:S360.
  13. Davey AL, Britland A, Naylor RJ. Decreasing paediatric prescribing errors in a district general hospital. Qual Saf Health Care 2008; 17:146.
  14. Jha AK, Kuperman GJ, Rittenberg E, et al. Identifying hospital admissions due to adverse drug events using a computer-based monitor. Pharmacoepidemiol Drug Saf 2001; 10:113.
  15. Flynn EA, Barker KN, Pepper GA, et al. Comparison of methods for detecting medication errors in 36 hospitals and skilled-nursing facilities. Am J Health Syst Pharm 2002; 59:436.
  16. Scarsi KK, Fotis MA, Noskin GA. Pharmacist participation in medical rounds reduces medication errors. Am J Health Syst Pharm 2002; 59:2089.
  17. Boockvar KS, Carlson LaCorte H, Giambanco V, et al. Medication reconciliation for reducing drug-discrepancy adverse events. Am J Geriatr Pharmacother 2006; 4:236.
  18. Cornish PL, Knowles SR, Marchesano R, et al. Unintended medication discrepancies at the time of hospital admission. Arch Intern Med 2005; 165:424.
  19. Forster AJ, Murff HJ, Peterson JF, et al. Adverse drug events occurring following hospital discharge. J Gen Intern Med 2005; 20:317.
  20. Pham JC, Story JL, Hicks RW, et al. National study on the frequency, types, causes, and consequences of voluntarily reported emergency department medication errors. J Emerg Med 2011; 40:485.
  21. Rothschild JM, Churchill W, Erickson A, et al. Medication errors recovered by emergency department pharmacists. Ann Emerg Med 2010; 55:513.
  22. Croskerry P, Shapiro M, Campbell S, et al. Profiles in patient safety: medication errors in the emergency department. Acad Emerg Med 2004; 11:289.
  23. Kozer E, Scolnik D, Macpherson A, et al. Variables associated with medication errors in pediatric emergency medicine. Pediatrics 2002; 110:737.
  24. Kothari D, Gupta S, Sharma C, Kothari S. Medication error in anaesthesia and critical care: A cause for concern. Indian J Anaesth 2010; 54:187.
  25. Glavin RJ. Drug errors: consequences, mechanisms, and avoidance. Br J Anaesth 2010; 105:76.
  26. Wheeler SJ, Wheeler DW. Medication errors in anaesthesia and critical care. Anaesthesia 2005; 60:257.
  27. Hicks RW, Becker SC, Krenzischeck D, Beyea SC. Medication errors in the PACU: a secondary analysis of MEDMARX findings. J Perianesth Nurs 2004; 19:18.
  28. Peth HA Jr. Medication errors in the emergency department: a systems approach to minimizing risk. Emerg Med Clin North Am 2003; 21:141.
  29. Kalina M, Tinkoff G, Gleason W, et al. A multidisciplinary approach to adverse drug events in pediatric trauma patients in an adult trauma center. Pediatr Emerg Care 2009; 25:444.
  30. Cullen DJ, Sweitzer BJ, Bates DW, et al. Preventable adverse drug events in hospitalized patients: a comparative study of intensive care and general care units. Crit Care Med 1997; 25:1289.
  31. Kopp BJ, Erstad BL, Allen ME, et al. Medication errors and adverse drug events in an intensive care unit: direct observation approach for detection. Crit Care Med 2006; 34:415.
  32. Wilmer A, Louie K, Dodek P, et al. Incidence of medication errors and adverse drug events in the ICU: a systematic review. Qual Saf Health Care 2010; 19:e7.
  33. Kane-Gill S, Weber RJ. Principles and practices of medication safety in the ICU. Crit Care Clin 2006; 22:273.
  34. Shane R. Current status of administration of medicines. Am J Health Syst Pharm 2009; 66:S42.
  35. Bell CM, Brener SS, Gunraj N, et al. Association of ICU or hospital admission with unintentional discontinuation of medications for chronic diseases. JAMA 2011; 306:840.
  36. Miller AD, Piro CC, Rudisill CN, et al. Nighttime and weekend medication error rates in an inpatient pediatric population. Ann Pharmacother 2010; 44:1739.
  37. Kaushal R, Bates DW, Landrigan C, et al. Medication errors and adverse drug events in pediatric inpatients. JAMA 2001; 285:2114.
  38. Takata GS, Mason W, Taketomo C, et al. Development, testing, and findings of a pediatric-focused trigger tool to identify medication-related harm in US children's hospitals. Pediatrics 2008; 121:e927.
  39. Beijer HJ, de Blaey CJ. Hospitalisations caused by adverse drug reactions (ADR): a meta-analysis of observational studies. Pharm World Sci 2002; 24:46.
  40. Gray SL, Sager M, Lestico MR, Jalaluddin M. Adverse drug events in hospitalized elderly. J Gerontol A Biol Sci Med Sci 1998; 53:M59.
  41. Evans RS, Lloyd JF, Stoddard GJ, et al. Risk factors for adverse drug events: a 10-year analysis. Ann Pharmacother 2005; 39:1161.
  42. Gurwitz JH, Field TS, Judge J, et al. The incidence of adverse drug events in two large academic long-term care facilities. Am J Med 2005; 118:251.
  43. Miller MR, Clark JS, Lehmann CU. Computer based medication error reporting: insights and implications. Qual Saf Health Care 2006; 15:208.
  44. Ghaleb MA, Barber N, Franklin BD, et al. Systematic review of medication errors in pediatric patients. Ann Pharmacother 2006; 40:1766.
  45. Murff HJ, Patel VL, Hripcsak G, Bates DW. Detecting adverse events for patient safety research: a review of current methodologies. J Biomed Inform 2003; 36:131.
  46. Desikan R, Krauss MJ, Dunagan WC, et al. Reporting of Adverse Drug Events: Examination of a Hospital Incident Reporting System. In: Advances in Patient Safety: From Research to Implementation, Henriksen K, Battles JB, Marks ES, Lewin DI (Eds), Agency for Healthcare Research and Quality (US), Rockville, MD 2005. Vol 1 (Research Findings).
  47. Jha AK, Kuperman GJ, Teich JM, et al. Identifying adverse drug events: development of a computer-based monitor and comparison with chart review and stimulated voluntary report. J Am Med Inform Assoc 1998; 5:305.
  48. Kilbridge PM, Campbell UC, Cozart HB, Mojarrad MG. Automated surveillance for adverse drug events at a community hospital and an academic medical center. J Am Med Inform Assoc 2006; 13:372.
  49. Gandhi TK, Weingart SN, Borus J, et al. Adverse drug events in ambulatory care. N Engl J Med 2003; 348:1556.
  50. Carnevali L, Krug B, Amant F, et al. Performance of the adverse drug event trigger tool and the global trigger tool for identifying adverse drug events: experience in a Belgian hospital. Ann Pharmacother 2013; 47:1414.
  51. Marcum ZA, Arbogast KL, Behrens MC, et al. Utility of an adverse drug event trigger tool in Veterans Affairs nursing facilities. Consult Pharm 2013; 28:99.
  52. Rozich JD, Haraden CR, Resar RK. Adverse drug event trigger tool: a practical methodology for measuring medication related harm. Qual Saf Health Care 2003; 12:194.
  53. Sammer C, Miller S, Jones C, et al. Developing and Evaluating an Automated All-Cause Harm Trigger System. Jt Comm J Qual Patient Saf 2017; 43:155.
  54. Weissman JS, Schneider EC, Weingart SN, et al. Comparing patient-reported hospital adverse events with medical record review: do patients know something that hospitals do not? Ann Intern Med 2008; 149:100.
  55. Key findings and recommendations on reporting and learning systems for patient safety incidents across Europe. Reporting and Leaning Subgroup of the European Commission. May 2014. http://ec.europa.eu/health/patient_safety/policy/index_en.htm (Accessed on February 11, 2015).
  56. Khan A, Coffey M, Litterer KP, et al. Families as Partners in Hospital Error and Adverse Event Surveillance. JAMA Pediatr 2017; 171:372.
  57. Schiff GD, Seoane-Vazquez E, Wright A. Incorporating Indications into Medication Ordering--Time to Enter the Age of Reason. N Engl J Med 2016; 375:306.
  58. Dowell D, Haegerich TM, Chou R. CDC Guideline for Prescribing Opioids for Chronic Pain - United States, 2016. MMWR Recomm Rep 2016; 65:1.
  59. Sarkar U, López A, Maselli JH, Gonzales R. Adverse drug events in U.S. adult ambulatory medical care. Health Serv Res 2011; 46:1517.
  60. Mihajlovic S, Gauthier J, MacDonald E. Patient Characteristics Associated with Adverse Drug Events in Hospital: An Overview of Reviews. Can J Hosp Pharm 2016; 69:294.
  61. Garfinkel D, Mangin D. Feasibility study of a systematic approach for discontinuation of multiple medications in older adults: addressing polypharmacy. Arch Intern Med 2010; 170:1648.
  62. Holbrook AM, Pereira JA, Labiris R, et al. Systematic overview of warfarin and its drug and food interactions. Arch Intern Med 2005; 165:1095.
  63. Juurlink DN, Mamdani M, Kopp A, et al. Drug-drug interactions among elderly patients hospitalized for drug toxicity. JAMA 2003; 289:1652.
  64. Reason J. Human error: models and management. BMJ 2000; 320:768.
  65. Leape LL. Error in medicine. JAMA 1994; 272:1851.
  66. Kaushal R, Shojania KG, Bates DW. Effects of computerized physician order entry and clinical decision support systems on medication safety: a systematic review. Arch Intern Med 2003; 163:1409.
  67. Forni A, Chu HT, Fanikos J. Technology utilization to prevent medication errors. Curr Drug Saf 2010; 5:13.
  68. Agrawal A. Medication errors: prevention using information technology systems. Br J Clin Pharmacol 2009; 67:681.
  69. Colpaert K, Claus B, Somers A, et al. Impact of computerized physician order entry on medication prescription errors in the intensive care unit: a controlled cross-sectional trial. Crit Care 2006; 10:R21.
  70. van Doormaal JE, van den Bemt PM, Zaal RJ, et al. The influence that electronic prescribing has on medication errors and preventable adverse drug events: an interrupted time-series study. J Am Med Inform Assoc 2009; 16:816.
  71. Walsh KE, Landrigan CP, Adams WG, et al. Effect of computer order entry on prevention of serious medication errors in hospitalized children. Pediatrics 2008; 121:e421.
  72. Bates DW, Leape LL, Cullen DJ, et al. Effect of computerized physician order entry and a team intervention on prevention of serious medication errors. JAMA 1998; 280:1311.
  73. Chertow GM, Lee J, Kuperman GJ, et al. Guided medication dosing for inpatients with renal insufficiency. JAMA 2001; 286:2839.
  74. Koppel R, Metlay JP, Cohen A, et al. Role of computerized physician order entry systems in facilitating medication errors. JAMA 2005; 293:1197.
  75. Nebeker JR, Hoffman JM, Weir CR, et al. High rates of adverse drug events in a highly computerized hospital. Arch Intern Med 2005; 165:1111.
  76. Ash JS, Sittig DF, Poon EG, et al. The extent and importance of unintended consequences related to computerized provider order entry. J Am Med Inform Assoc 2007; 14:415.
  77. Brown CL, Mulcaster HL, Triffitt KL, et al. A systematic review of the types and causes of prescribing errors generated from using computerized provider order entry systems in primary and secondary care. J Am Med Inform Assoc 2017; 24:432.
  78. Amato MG, Salazar A, Hickman TT, et al. Computerized prescriber order entry-related patient safety reports: analysis of 2522 medication errors. J Am Med Inform Assoc 2017; 24:316.
  79. Bates DW. Using information technology to reduce rates of medication errors in hospitals. BMJ 2000; 320:788.
  80. Kaushal R, Bates DW. Information technology and medication safety: what is the benefit? Qual Saf Health Care 2002; 11:261.
  81. Mekhjian HS, Kumar RR, Kuehn L, et al. Immediate benefits realized following implementation of physician order entry at an academic medical center. J Am Med Inform Assoc 2002; 9:529.
  82. Poon EG, Keohane CA, Yoon CS, et al. Effect of bar-code technology on the safety of medication administration. N Engl J Med 2010; 362:1698.
  83. Mahoney CD, Berard-Collins CM, Coleman R, et al. Effects of an integrated clinical information system on medication safety in a multi-hospital setting. Am J Health Syst Pharm 2007; 64:1969.
  84. Larsen GY, Parker HB, Cash J, et al. Standard drug concentrations and smart-pump technology reduce continuous-medication-infusion errors in pediatric patients. Pediatrics 2005; 116:e21.
  85. Rothschild JM, Keohane CA, Cook EF, et al. A controlled trial of smart infusion pumps to improve medication safety in critically ill patients. Crit Care Med 2005; 33:533.
  86. Nuckols TK, Bower AG, Paddock SM, et al. Programmable infusion pumps in ICUs: an analysis of corresponding adverse drug events. J Gen Intern Med 2008; 23 Suppl 1:41.
  87. Husch M, Sullivan C, Rooney D, et al. Insights from the sharp end of intravenous medication errors: implications for infusion pump technology. Qual Saf Health Care 2005; 14:80.
  88. Bates DW, Vanderveen T, Seger D, et al. Variability in intravenous medication practices: implications for medication safety. Jt Comm J Qual Patient Saf 2005; 31:203.
  89. McAlearney AS, Vrontos J Jr, Schneider PJ, et al. Strategic Work-Arounds to Accommodate New Technology: The Case of Smart Pumps in Hospital Care. J Patient Saf 2007; 3:75.
  90. Russell RA, Murkowski K, Scanlon MC. Discrepancies between medication orders and infusion pump programming in a paediatric intensive care unit. Qual Saf Health Care 2010; 19 Suppl 3:i31.
  91. Kaboli PJ, Hoth AB, McClimon BJ, Schnipper JL. Clinical pharmacists and inpatient medical care: a systematic review. Arch Intern Med 2006; 166:955.
  92. Kaushal R, Bates DW, Abramson EL, et al. Unit-based clinical pharmacists' prevention of serious medication errors in pediatric inpatients. Am J Health Syst Pharm 2008; 65:1254.
  93. Bladh L, Ottosson E, Karlsson J, et al. Effects of a clinical pharmacist service on health-related quality of life and prescribing of drugs: a randomised controlled trial. BMJ Qual Saf 2011; 20:738.
  94. Al-Rashed SA, Wright DJ, Roebuck N, et al. The value of inpatient pharmaceutical counselling to elderly patients prior to discharge. Br J Clin Pharmacol 2002; 54:657.
  95. Schnipper JL, Kirwin JL, Cotugno MC, et al. Role of pharmacist counseling in preventing adverse drug events after hospitalization. Arch Intern Med 2006; 166:565.
  96. Abdel-Qader DH, Harper L, Cantrill JA, Tully MP. Pharmacists' interventions in prescribing errors at hospital discharge: an observational study in the context of an electronic prescribing system in a UK teaching hospital. Drug Saf 2010; 33:1027.
  97. Leape LL, Cullen DJ, Clapp MD, et al. Pharmacist participation on physician rounds and adverse drug events in the intensive care unit. JAMA 1999; 282:267.
  98. Klopotowska JE, Kuiper R, van Kan HJ, et al. On-ward participation of a hospital pharmacist in a Dutch intensive care unit reduces prescribing errors and related patient harm: an intervention study. Crit Care 2010; 14:R174.
  99. Kucukarslan SN, Peters M, Mlynarek M, Nafziger DA. Pharmacists on rounding teams reduce preventable adverse drug events in hospital general medicine units. Arch Intern Med 2003; 163:2014.
  100. Lee JY, Leblanc K, Fernandes OA, et al. Medication reconciliation during internal hospital transfer and impact of computerized prescriber order entry. Ann Pharmacother 2010; 44:1887.
  101. Wong JD, Bajcar JM, Wong GG, et al. Medication reconciliation at hospital discharge: evaluating discrepancies. Ann Pharmacother 2008; 42:1373.
  102. Mueller SK, Sponsler KC, Kripalani S, Schnipper JL. Hospital-based medication reconciliation practices: a systematic review. Arch Intern Med 2012; 172:1057.
  103. Greenwald JL, Halasyamani L, Greene J, et al. Making inpatient medication reconciliation patient centered, clinically relevant and implementable: a consensus statement on key principles and necessary first steps. J Hosp Med 2010; 5:477.
  104. Potential inaccuracy of electronically transmitted medication history information used for medication reconciliation http://www.ismp.org/NAN/default.asp (Accessed on February 19, 2014).
  105. Leonard MS, Cimino M, Shaha S, et al. Risk reduction for adverse drug events through sequential implementation of patient safety initiatives in a children's hospital. Pediatrics 2006; 118:e1124.
  106. Trivalle C, Cartier T, Verny C, et al. Identifying and preventing adverse drug events in elderly hospitalised patients: a randomised trial of a program to reduce adverse drug effects. J Nutr Health Aging 2010; 14:57.
  107. Kuperman GJ, Gandhi TK, Bates DW. Effective drug-allergy checking: methodological and operational issues. J Biomed Inform 2003; 36:70.
  108. Zimmerman CR, Chaffee BW, Lazarou J, et al. Maintaining the enterprisewide continuity and interoperability of patient allergy data. Am J Health Syst Pharm 2009; 66:671.
  109. Bates DW, Teich JM, Lee J, et al. The impact of computerized physician order entry on medication error prevention. J Am Med Inform Assoc 1999; 6:313.