Adverse drug events in hospitalized patients. Excess length of stay, extra costs, and attributable mortality

D. C. Classen, S. L. Pestotnik, R. S. Evans, J. F. Lloyd and J. P. Burke
Department of Clinical Epidemiology, LDS Hospital, Salt Lake City, UT 84143, USA.

OBJECTIVE: To determine the excess length of stay, extra costs, and mortality attributable to adverse drug events (ADEs) in hospitalized patients. DESIGN: Matched case-control study. SETTING: The LDS Hospital, a tertiary care health care institution. PATIENTS: All patients admitted to LDS Hospital from January 1, 1990, to December 31, 1993, were eligible. Cases were defined as patients with ADEs that occurred during hospitalization; controls were selected according to matching variables in a stepwise fashion. METHODS: Controls were matched to cases on primary discharge diagnosis related group (DRG), age, sex, acuity, and year of admission; varying numbers of controls were matched to each case. Matching was successful for 71% of the cases, leading to 1580 cases and 20,197 controls. MAIN OUTCOME MEASURES: Crude and attributable mortality, crude and attributable length of stay, and cost of hospitalization. RESULTS: ADEs complicated 2.43 per 100 admissions to the LDS Hospital during the study period. The crude mortality rates for the cases and matched controls were 3.5% and 1.05%, respectively (P<.001). The mean length of hospital stay significantly differed between the cases and matched controls (7.69 vs 4.46 days; P<.001) as did the mean cost of hospitalization ($10,010 vs $5355; P<.001). The extra length of hospital stay attributable to an ADE was 1.74 days (P<.001). The excess cost of hospitalization attributable to an ADE was $2013 (P<.001). A linear regression analysis for length of stay and cost controlling for all matching variables revealed that the occurrence of an ADE was associated with increased length of stay of 1.91 days and an increased cost of $2262 (P<.001). In a similar logistic regression analysis for mortality, the increased risk of death among patients experiencing an ADE was 1.88 (95% confidence interval, 1.54-2.22; P<.001). CONCLUSION: The attributable lengths of stay and costs of hospitalization for ADEs are substantial. An ADE is associated with a significantly prolonged length of stay, increased economic burden, and an almost 2-fold increased risk of death.

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

Detection and prevention of medication misadventures in general practice
Tam et al.
Int J Qual Health Care 2008;20:192-199.
ABSTRACT | FULL TEXT  

Factors influencing bar-code verification by nurses during medication administration in a Dutch hospital
van Onzenoort et al.
Am J Health Syst Pharm 2008;65:644-648.
ABSTRACT | FULL TEXT  

Predictors of Medication Errors Among Elderly Hospitalized Patients
Picone et al.
American Journal of Medical Quality 2008;23:115-127.
ABSTRACT  

Effective interventions and implementation strategies to reduce adverse drug events in the Veterans Affairs (VA) system
Mills et al.
Qual Saf Health Care 2008;17:37-46.
ABSTRACT | FULL TEXT  

The Effect of Drug Concentration Expression on Epinephrine Dosing Errors: A Randomized Trial
Wheeler et al.
ANN INTERN MED 2008;148:11-14.
ABSTRACT | FULL TEXT  

Medication Use Leading to Emergency Department Visits for Adverse Drug Events in Older Adults
Budnitz et al.
ANN INTERN MED 2007;147:755-765.
ABSTRACT | FULL TEXT  

Evaluation of an Electronic Critical Drug Interaction Program Coupled with Active Pharmacist Intervention
Humphries et al.
The Annals of Pharmacotherapy 2007;41:1979-1985.
ABSTRACT | FULL TEXT  

Impact of Computerized Prescriber Order Entry on the Incidence of Adverse Drug Events in Pediatric Inpatients
Holdsworth et al.
Pediatrics 2007;120:1058-1066.
ABSTRACT | FULL TEXT  

The Utility of Adding Retrospective Medication Profiling to Computerized Provider Order Entry in an Ambulatory Care Population
Glassman et al.
J. Am. Med. Inform. Assoc. 2007;14:424-431.
ABSTRACT | FULL TEXT  

A Systematic Review of the Performance Characteristics of Clinical Event Monitor Signals Used to Detect Adverse Drug Events in the Hospital Setting
Handler et al.
J. Am. Med. Inform. Assoc. 2007;14:451-458.
ABSTRACT | FULL TEXT  

ASHP Long-Range Vision for the Pharmacy Work Force in Hospitals and Health Systems: Ensuring the Best Use of Medicines in Hospitals and Health Systems
Am J Health Syst Pharm 2007;64:1320-1330.
FULL TEXT  

Electronic Prescribing Systems in Pediatrics: The Rationale and Functionality Requirements
Gerstle et al.
Pediatrics 2007;119:e1413-e1422.
ABSTRACT | FULL TEXT  

The cost of pneumonia after acute stroke
Katzan et al.
Neurology 2007;68:1938-1943.
ABSTRACT | FULL TEXT  

Medication errors in inpatient pharmacy operations and technologies for improvement
Kuiper et al.
Am J Health Syst Pharm 2007;64:955-959.
FULL TEXT  

Managing Complex Medication Regimens: Perspectives of Consumers with Osteoarthritis and Healthcare Professionals
Manias et al.
The Annals of Pharmacotherapy 2007;41:764-771.
ABSTRACT | FULL TEXT  

Cost-Benefit Analysis of a Hospital Pharmacy Bar Code Solution
Maviglia et al.
Arch Intern Med 2007;167:788-794.
ABSTRACT | FULL TEXT  

Multidisciplinary approach to inpatient medication reconciliation in an academic setting
Varkey et al.
Am J Health Syst Pharm 2007;64:850-854.
ABSTRACT | FULL TEXT  

An ounce of prevention: A pound of cure for an ailing health care system
Genuis
cfp 2007;53:597-599.
FULL TEXT  

Une once de prevention: Prescription pour un systeme de sante en dif_culte
Genuis
cfp 2007;53:605-607.
FULL TEXT  

Developing a model to determine the effects of adverse drug events in hospital inpatients
Nilsen and Fotis
Am J Health Syst Pharm 2007;64:521-525.
ABSTRACT | FULL TEXT  

Implementation of an electronic system for medication reconciliation
Kramer et al.
Am J Health Syst Pharm 2007;64:404-422.
ABSTRACT | FULL TEXT  

Epidemiology, Complications, and Cost of Hospitalization in Children With Laboratory-Confirmed Influenza Infection
Ampofo et al.
Pediatrics 2006;118:2409-2417.
ABSTRACT | FULL TEXT  

Assessment of adverse drug events among patients in a tertiary care medical center
Johnston et al.
Am J Health Syst Pharm 2006;63:2218-2227.
ABSTRACT | FULL TEXT  

Escalating polypharmacy
Gorard
QJM 2006;99:797-800.
ABSTRACT | FULL TEXT  

National surveillance of emergency department visits for outpatient adverse drug events.
Budnitz et al.
JAMA 2006;296:1858-1866.
ABSTRACT | FULL TEXT  

Adverse-drug-event rates for high-cost and high-use drugs in the intensive care unit.
Kane-Gill et al.
Am J Health Syst Pharm 2006;63:1876-1881.
ABSTRACT | FULL TEXT  

Risk Reduction for Adverse Drug Events Through Sequential Implementation of Patient Safety Initiatives in a Children's Hospital
Leonard et al.
Pediatrics 2006;118:e1124-e1129.
ABSTRACT | FULL TEXT  

Improved therapeutic monitoring with several interventions: a randomized trial.
Feldstein et al.
Arch Intern Med 2006;166:1848-1854.
ABSTRACT | FULL TEXT  

Association of perceived medical errors with resident distress and empathy: a prospective longitudinal study.
West et al.
JAMA 2006;296:1071-1078.
ABSTRACT | FULL TEXT  

Improving self-reporting of adverse drug events in a west virginia hospital.
Schade et al.
American Journal of Medical Quality 2006;21:335-341.
ABSTRACT  

Improving the bar-coded medication administration system at the Department of Veterans Affairs.
Mills et al.
Am J Health Syst Pharm 2006;63:1442-1447.
FULL TEXT  

Adverse Drug Reactions Among Children Over a 10-Year Period
Le et al.
Pediatrics 2006;118:555-562.
ABSTRACT | FULL TEXT  

Study of Medication Errors on a Community Hospital Oncology Ward
Ford et al.
J Oncol Pract 2006;2:149-154.
ABSTRACT | FULL TEXT  

Treatment outcomes in patients receiving conventional amphotericin B therapy: a prospective multicentre study in Taiwan
Chen et al.
J Antimicrob Chemother 2006;57:1181-1188.
ABSTRACT | FULL TEXT  

Systematic Review: Impact of Health Information Technology on Quality, Efficiency, and Costs of Medical Care
Chaudhry et al.
ANN INTERN MED 2006;144:742-752.
ABSTRACT | FULL TEXT  

Effect of internal reporting criteria on suspected adverse drug reactions submitted to MedWatch
Smith et al.
Am J Health Syst Pharm 2006;63:949-952.
FULL TEXT  

Return on Investment for a Computerized Physician Order Entry System
Kaushal et al.
J. Am. Med. Inform. Assoc. 2006;13:261-266.
ABSTRACT | FULL TEXT  

Development of the Leapfrog methodology for evaluating hospital implemented inpatient computerized physician order entry systems.
Kilbridge et al.
Qual Saf Health Care 2006;15:81-84.
ABSTRACT | FULL TEXT  

Reconcilable differences: correcting medication errors at hospital admission and discharge.
Vira et al.
Qual Saf Health Care 2006;15:122-126.
ABSTRACT | FULL TEXT  

Relationship of Medication Use to Health-Related Quality of Life Among a Group of Older American Indians
Henderson et al.
Journal of Applied Gerontology 2006;25:89S-104S.
ABSTRACT  

The Long Road to Patient Safety: A Status Report on Patient Safety Systems
Longo et al.
JAMA 2005;294:2858-2865.
ABSTRACT | FULL TEXT  

Unexpected Increased Mortality After Implementation of a Commercially Sold Computerized Physician Order Entry System
Han et al.
Pediatrics 2005;116:1506-1512.
ABSTRACT | FULL TEXT  

Bar-code verification of medication administration in a small hospital
Lawton and Shields
Am J Health Syst Pharm 2005;62:2413-2415.
FULL TEXT  

Drug-Related Visits to the Emergency Department
Zed
Journal of Pharmacy Practice 2005;18:329-335.
ABSTRACT  

Pharmacist intervention when interacting drugs are prescribed despite alerts
Chan
Am J Health Syst Pharm 2005;62:1760-1763.
FULL TEXT  

Use of specific indicators to detect warfarin-related adverse events
Hartis et al.
Am J Health Syst Pharm 2005;62:1683-1688.
ABSTRACT | FULL TEXT  

Dietary supplement-related adverse events reported to the California Poison Control System
Dennehy et al.
Am J Health Syst Pharm 2005;62:1476-1482.
ABSTRACT | FULL TEXT  

Accuracy of adverse-drug-event reports collected using an automated dispensing system
Romero and Malone
Am J Health Syst Pharm 2005;62:1375-1380.
ABSTRACT | FULL TEXT  

Comprehensive Analysis of a Medication Dosing Error Related to CPOE
Horsky et al.
J. Am. Med. Inform. Assoc. 2005;12:377-382.
ABSTRACT | FULL TEXT  

Risk Factors for Adverse Drug Events: A 10-Year Analysis
Evans et al.
The Annals of Pharmacotherapy 2005;39:1161-1168.
ABSTRACT | FULL TEXT  

Epidemiology, Comparative Methods of Detection, and Preventability of Adverse Drug Events
Al-Tajir and Kelly
The Annals of Pharmacotherapy 2005;39:1169-1174.
ABSTRACT | FULL TEXT  

Medication safety program reduces adverse drug events in a community hospital
Cohen et al.
Qual Saf Health Care 2005;14:169-174.
ABSTRACT | FULL TEXT  

Factors predictive of intravenous fluid administration errors in Australian surgical care wards
Han et al.
Qual Saf Health Care 2005;14:179-184.
ABSTRACT | FULL TEXT  

Improving medication management for patients: the effect of a pharmacist on post-admission ward rounds
Fertleman et al.
Qual Saf Health Care 2005;14:207-211.
ABSTRACT | FULL TEXT  

Fostering Rational Regulation of Patient Safety
Mello et al.
Journal of Health Politics, Policy and Law 2005;30:375-426.
ABSTRACT  

High Rates of Adverse Drug Events in a Highly Computerized Hospital
Nebeker et al.
Arch Intern Med 2005;165:1111-1116.
ABSTRACT | FULL TEXT  

A Trial of Automated Decision Support Alerts for Contraindicated Medications Using Computerized Physician Order Entry
Galanter et al.
J. Am. Med. Inform. Assoc. 2005;12:269-274.
ABSTRACT | FULL TEXT  

Concealed Renal Insufficiency and Adverse Drug Reactions in Elderly Hospitalized Patients
Corsonello et al.
Arch Intern Med 2005;165:790-795.
ABSTRACT | FULL TEXT  

Error Reporting and Disclosure Systems: Views From Hospital Leaders
Weissman et al.
JAMA 2005;293:1359-1366.
ABSTRACT | FULL TEXT  

Reducing Excessive Medication Administration in Hospitalized Adults With Renal Dysfunction
Nash et al.
American Journal of Medical Quality 2005;20:64-69.
ABSTRACT  

Oxymorphone Extended Release Does Not Affect CYP2C9 or CYP3A4 Metabolic Pathways
Adams et al.
J Clin Pharmacol 2005;45:337-345.
ABSTRACT | FULL TEXT  

Unintended Medication Discrepancies at the Time of Hospital Admission
Cornish et al.
Arch Intern Med 2005;165:424-429.
ABSTRACT | FULL TEXT  

Implementation of Hospital Computerized Physician Order Entry Systems in a Rural State: Feasibility and Financial Impact
Ohsfeldt et al.
J. Am. Med. Inform. Assoc. 2005;12:20-27.
ABSTRACT | FULL TEXT  

Patient Safety Forum: Should Psychologists Have Prescribing Authority?
Yates et al.
Psychiatr. Serv. 2004;55:1420-1426.
FULL TEXT  

A Drug Database Model as a Central Element for Computer-Supported Dose Adjustment within a CPOE System
Martin et al.
J. Am. Med. Inform. Assoc. 2004;11:427-432.
ABSTRACT | FULL TEXT  

Adverse drug reactions as cause of admission to hospital: prospective analysis of 18 820 patients
Pirmohamed et al.
BMJ 2004;329:15-19.
ABSTRACT | FULL TEXT  

A Trial of Automated Safety Alerts for Inpatient Digoxin Use with Computerized Physician Order Entry
Galanter et al.
J. Am. Med. Inform. Assoc. 2004;11:270-277.
ABSTRACT | FULL TEXT  

Information Resources Used in Antimicrobial Prescribing
Sellman et al.
J. Am. Med. Inform. Assoc. 2004;11:281-284.
ABSTRACT | FULL TEXT  

Using Pharmacogenetics to Improve Drug Safety and Efficacy
Haga and Burke
JAMA 2004;291:2869-2871.
FULL TEXT  

Comparison of Drug-Related Problems in Different Patient Groups
Viktil et al.
The Annals of Pharmacotherapy 2004;38:942-948.
ABSTRACT | FULL TEXT  

Clinical Informatics in Critical Care
Martich et al.
J Intensive Care Med 2004;19:154-163.
ABSTRACT  

The Effect of a Computerized Reminder System on the Prevention of Postoperative Venous Thromboembolism
Mosen et al.
Chest 2004;125:1635-1641.
ABSTRACT | FULL TEXT  

Compliance with Dosing Guidelines in Patients with Chronic Kidney Disease
Long et al.
The Annals of Pharmacotherapy 2004;38:853-858.
ABSTRACT | FULL TEXT  

The Epidemiology of Prescribing Errors: The Potential Impact of Computerized Prescriber Order Entry
Bobb et al.
Arch Intern Med 2004;164:785-792.
ABSTRACT | FULL TEXT  

A 52-Year-Old Man With Pulmonary Edema Following Large-Volume Transfusion
Wolfenden and Fessler
Chest 2004;125:1556-1560.
FULL TEXT  

Patient and Staff Safety: Voluntary Reporting
Blegen et al.
American Journal of Medical Quality 2004;19:67-74.
ABSTRACT  

Computerized Physician Order Entry: Helpful or Harmful?
Berger and Kichak
J. Am. Med. Inform. Assoc. 2004;11:100-103.
ABSTRACT | FULL TEXT  

Evolution of a Rapid Hydration Protocol
Tracy et al.
Journal of Pediatric Oncology Nursing 2004;21:22-26.
ABSTRACT  

Computerized Physician Order Entry and Medication Errors in a Pediatric Critical Care Unit
Potts et al.
Pediatrics 2004;113:59-63.
ABSTRACT | FULL TEXT  

Methodology and rationale for the measurement of harm with trigger tools
Resar et al.
Qual Saf Health Care 2003;12:ii39-45.
ABSTRACT | FULL TEXT  

Administrative data based patient safety research: a critical review
Zhan and Miller
Qual Saf Health Care 2003;12:ii58-63.
ABSTRACT | FULL TEXT  

The Impact of Dedicated Medication Nurses on the Medication Administration Error Rate: A Randomized Controlled Trial
Greengold et al.
Arch Intern Med 2003;163:2359-2367.
ABSTRACT | FULL TEXT  

Excess Length of Stay, Charges, and Mortality Attributable to Medical Injuries During Hospitalization
Zhan and Miller
JAMA 2003;290:1868-1874.
ABSTRACT | FULL TEXT  

Review Article: Patient Safety in Geriatrics: A Call for Action
Tsilimingras et al.
J. Gerontol. A Biol. Sci. Med. Sci. 2003;58:M813-819.
ABSTRACT | FULL TEXT  

The Effect of Computerized Physician Order Entry on Medication Errors and Adverse Drug Events in Pediatric Inpatients
King et al.
Pediatrics 2003;112:506-509.
ABSTRACT | FULL TEXT  

Minimizing Medication Errors: Practical Pointers for Prescribers
Benjamin
J Clin Pharmacol 2003;43:751-753.
FULL TEXT  

Effects of Computerized Physician Order Entry and Clinical Decision Support Systems on Medication Safety: A Systematic Review
Kaushal et al.
Arch Intern Med 2003;163:1409-1416.
ABSTRACT | FULL TEXT  

Medication Errors in Hospitalized Cardiovascular Patients
LaPointe and Jollis
Arch Intern Med 2003;163:1461-1466.
ABSTRACT | FULL TEXT  

Adverse drug event trigger tool: a practical methodology for measuring medication related harm
Rozich et al.
Qual Saf Health Care 2003;12:194-200.
ABSTRACT | FULL TEXT  

Use of Chart and Record Reviews to Detect Medication Errors in a State Psychiatric Hospital
Grasso et al.
Psychiatr. Serv. 2003;54:677-681.
ABSTRACT | FULL TEXT  

Adverse Drug Events in Ambulatory Care
Gandhi et al.
NEJM 2003;348:1556-1564.
ABSTRACT | FULL TEXT  

Prioritizing Strategies for Preventing Medication Errors and Adverse Drug Events in Pediatric Inpatients
Fortescue et al.
Pediatrics 2003;111:722-729.
ABSTRACT | FULL TEXT  

Incidence and Preventability of Adverse Drug Events Among Older Persons in the Ambulatory Setting
Gurwitz et al.
JAMA 2003;289:1107-1116.
ABSTRACT | FULL TEXT  

Adverse Drug Events Associated with Hospital Admission
Peyriere et al.
The Annals of Pharmacotherapy 2003;37:5-11.
ABSTRACT | FULL TEXT  

Incidence and Impact of Adverse Drug Events in Pediatric Inpatients
Holdsworth et al.
Arch Pediatr Adolesc Med 2003;157:60-65.
ABSTRACT | FULL TEXT  

Analysis of Medication-Related Malpractice Claims: Causes, Preventability, and Costs
Rothschild et al.
Arch Intern Med 2002;162:2414-2420.
ABSTRACT | FULL TEXT  

Using a Clinical Data Repository to Estimate the Frequency and Costs of Adverse Drug Events
Einbinder and Scully
J. Am. Med. Inform. Assoc. 2002;9:S34-38.
ABSTRACT | FULL TEXT  

Developing a Taxonomy for Research in Adverse Drug Events: Potholes and Signposts
Nebeker et al.
J. Am. Med. Inform. Assoc. 2002;9:S80-85.
ABSTRACT | FULL TEXT