Institute of Medicine Report

1999 Institute of Medicine Report

The 1999 Institute of Medicine Report concluded that from 44,000 to 98,000 people die annually due to errors in inpatient hospital treatment. Hundreds of articles on medical errors have cited the Institute of Medicine Report.

According to Dr. Lucien Leape, lead the author of the Harvard study, the number of deaths from medical errors in hospitals account for the equivalent to the death toll from three jumbo jet crashes every two days. Public Health Reports, 1999; 114: 302-317 July / August, 1999. One in every 10 patients admitted to a hospital is the victim of at least one mistake. National Public Radio (NPR) November 21, 2000, (Audio)

Only 1.53 percent of patients who were harmed by medical treatment filed malpractice claims.
N Engl J Med 1989 Aug 17;321(7):480-4

Five years after I.O.M. report, medical errors still claiming many lives - U.S.A. today (archived)

About the Institute of Medicine Report:
     - How the IOM arrived at their estimate of 44,000 - 98,00 deaths due to hospital errors.
           Adverse events occurred in 3.7 percent of the hospitalizations.
           The nature of adverse events in hospitalized patients.
           1.5% of injured patients filed malpractice suits.
        Summaries of the original data.

     Articles Citing the IOM Report:
                          - Headlines: 1999.2000.2001.2002.2003.2004.2005.2006.2007.
                         - Leads:        1999.2000.2001.2002.2003.2004.2005.2006.2007.

From To Err Is Human: Building a Safer Health System
Executive Summary - Page 1 Linda T. Kohn, Janet M. Corrigan, and Molla S. Donaldson, Editors;
Committee on Quality of Health Care in America, Institute of Medicine

Two large studies, one conducted in Colorado and Utah and the other in New York, found that adverse events occurred in 2.9 and 3.7 percent of hospitalizations, respectively. In Colorado and Utah hospitals, 6.6 percent of adverse events led to death, as compared with 13.6 percent in New York hospitals. In both of these studies, over half of these adverse events resulted from medical errors and could have been prevented.
When extrapolated to the over 33.6 million admissions to U.S. hospitals in 1997, the results of the study in Colorado and Utah imply that at least 44,000 Americans die each year as a result of medical errors. The results of the New York Study suggest the number may be as high as 98,000. Even when using the lower estimate, deaths due to medical errors exceed the number attributable to the 8th-leading cause of death. More people die in a given year as a result of medical errors than from motor vehicle accidents (43,458), breast cancer (42,297), or AIDS (16,516).

Abstracts from New England Journal of Medicine presenting the original New York findings: I . II . III .

Incidence of adverse events and negligence in hospitalized patients.                                                      TOP
    Results of the Harvard Medical Practice Study I.
Brennan TA, Leape LL, Laird NM, Hebert L, Localio AR, Lawthers AG, Newhouse JP, Weiler PC, Hiatt HH. Division of General Medicine, Brigham and Women's Hospital, Boston, MA 02115.
    N Engl J Med 1991 Feb 7;324(6):370-6
BACKGROUND. As part of an interdisciplinary study of medical injury and malpractice litigation, we estimated the incidence of adverse events, defined as injuries caused by medical management, and of the subgroup of such injuries that resulted from negligent or substandard care.
METHODS. We reviewed 30,121 randomly selected records from 51 randomly selected acute care, nonpsychiatric hospitals in New York State in 1984. We then developed population estimates of injuries and computed rates according to the age and sex of the patients as well as the specialties of the physicians.
RESULTS. Adverse events occurred in 3.7 percent of the hospitalizations (95 percent confidence interval, 3.2 to 4.2), and 27.6 percent of the adverse events were due to negligence (95 percent confidence interval, 22.5 to 32.6). Although 70.5 percent of the adverse events gave rise to disability lasting less than six months, 2.6 percent caused permanently disabling injuries and 13.6 percent led to death. The percentage of adverse events attributable to negligence increased in the categories of more severe injuries (Wald test chi 2 = 21.04, P less than 0.0001). Using weighted totals, we estimated that among the 2,671,863 patients discharged from New York hospitals in 1984 there were 98,609 adverse events and 27,179 adverse events involving negligence. Rates of adverse events rose with age (P less than 0.0001). The percentage of adverse events due to negligence was markedly higher among the elderly (P less than 0.01). There were significant differences in rates of adverse events among categories of clinical specialties (P less than 0.0001), but no differences in the percentage due to negligence.
CONCLUSIONS. There is a substantial amount of injury to patients from medical management, and many injuries are the result of substandard care. PMID: 1987460

The nature of adverse events in hospitalized patients.                                                       TOP
   Results of the Harvard Medical Practice Study II.
Leape LL, Brennan TA, Laird N, Lawthers AG, Localio AR, Barnes BA, Hebert L, Newhouse JP, Weiler PC, Hiatt H.
Department of Health Policy and Management, Harvard School of Public Health, Boston, MA 02115.
    N Engl J Med 1991 Feb 7;324(6):377-84
BACKGROUND. In a sample of 30,195 randomly selected hospital records, we identified 1133 patients (3.7 percent) with disabling injuries caused by medical treatment. We report here an analysis of these adverse events and their relation to error, negligence, and disability.
METHODS. Two physician-reviewers independently identified the adverse events and evaluated them with respect to negligence, errors in management, and extent of disability. One of the authors classified each event according to type of injury. We tested the significance of differences in rates of negligence and disability among categories with at least 30 adverse events.
RESULTS. Drug complications were the most common type of adverse event (19 percent), followed by wound infections (14 percent) and technical complications (13 percent). Nearly half the adverse events (48 percent) were associated with an operation. Adverse events during surgery were less likely to be caused by negligence (17 percent) than nonsurgical ones (37 percent). The proportion of adverse events due to negligence was highest for diagnostic mishaps (75 percent), noninvasive therapeutic mishaps ("errors of omission") (77 percent), and events occurring in the emergency room (70 percent). Errors in management were identified for 58 percent of the adverse events, among which nearly half were attributed to negligence.
CONCLUSIONS. Although the prevention of many adverse events must await improvements in medical knowledge, the high proportion that are due to management errors suggests that many others are potentially preventable now. Reducing the incidence of these events will require identifying their causes and developing methods to prevent error or reduce its effects.
PMID: 1824793

Relation between malpractice claims and adverse events due to negligence.                                     TOP
    Results of the Harvard Medical Practice Study III.
Localio AR, Lawthers AG, Brennan TA, Laird NM, Hebert LE, Peterson LM, Newhouse JP, Weiler PC, Hiatt HH.
Center for Biostatistics and Epidemiology, Penn State University College of Medicine, Hershey 17033.
N Engl J Med 1991 Jul 25;325(4):245-51
BACKGROUND AND METHODS. By matching the medical records of a random sample of 31,429 patients hospitalized in New York State in 1984 with statewide data on medical-malpractice claims, we identified patients who had filed claims against physicians and hospitals. These results were then compared with our findings, based on a review of the same medical records, regarding the incidence of injuries to patients caused by medical management (adverse events).
RESULTS. We identified 47 malpractice claims among 30,195 patients' records located on our initial visits to the hospitals, and 4 claims among 580 additional records located during follow-up visits. The overall rate of claims per discharge (weighted) was 0.13 percent (95 percent confidence interval, 0.076 to 0.18 percent). Of the 280 patients who had adverse events caused by medical negligence as defined by the study protocol, 8 filed malpractice claims (weighted rate, 1.53 percent; 95 percent confidence interval, 0 to 3.2 percent). By contrast, our estimate of the statewide ratio of adverse events caused by negligence (27,179) to malpractice claims (3570) is 7.6 to 1. This relative frequency overstates the chances that a negligent adverse event will produce a claim, however, because most of the events for which claims were made in the sample did not meet our definition of adverse events due to negligence.
CONCLUSIONS. Medical-malpractice litigation infrequently compensates patients injured by medical negligence and rarely identifies, and holds providers accountable for, substandard care.   PMID: 2057025

A study of medical injury and medical malpractice.
Hiatt HH, Barnes BA, Brennan TA, Laird NM, Lawthers AG, Leape LL, Localio AR, Newhouse JP, Peterson LM, Thorpe KE, et al. Harvard School of Public Health, Boston, MA 02115.
N Engl J Med 1989 Aug 17;321(7):480-4

Incidence and types of adverse events and negligent care in Utah and Colorado. TOP
Thomas EJ, Studdert DM, Burstin HR, Orav EJ, Zeena T, Williams EJ, Howard KM, Weiler PC, Brennan TA.
Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.
Med Care 2000 Mar;38(3):261-71
BACKGROUND: The ongoing debate on the incidence and types of iatrogenic injuries in American hospitals has been informed primarily by the Harvard Medical Practice Study, which analyzed hospitalizations in New York in 1984. The generalizability of these findings is unknown and has been questioned by other studies.
OBJECTIVE: We used methods similar to the Harvard Medical Practice Study to estimate the incidence and types of adverse events and negligent adverse events in Utah and Colorado in 1992.
DESIGN AND SUBJECTS: We selected a representative sample of hospitals from Utah and Colorado and then randomly sampled 15,000 nonpsychiatric 1992 discharges. Each record was screened by a trained nurse-reviewer for 1 of 18 criteria associated with adverse events. If > or =1 criteria were present, the record was reviewed by a trained physician to determine whether an adverse event or negligent adverse event occurred and to classify the type of adverse event.
MEASURES: The measures were adverse events and negligent adverse events.
RESULTS: Adverse events occurred in 2.9+/-0.2% (mean+/-SD) of hospitalizations in each state. In Utah, 32.6+/-4% of adverse events were due to negligence; in Colorado, 27.4+/-2.4%. Death occurred in 6.6+/-1.2% of adverse events and 8.8+/-2.5% of negligent adverse events. Operative adverse events comprised 44.9% of all adverse events; 16.9% were negligent, and 16.6% resulted in permanent disability. Adverse drug events were the leading cause of nonoperative adverse events (19.3% of all adverse events; 35.1% were negligent, and 9.7% caused permanent disability). Most adverse events were attributed to surgeons (46.1%, 22.3% negligent) and internists (23.2%, 44.9% negligent).
CONCLUSIONS: The incidence and types of adverse events in Utah and Colorado in 1992 were similar to those in New York State in 1984. Iatrogenic injury continues to be a significant public health problem. Improving systems of surgical care and drug delivery could substantially reduce the burden of iatrogenic injury. PMID: 10718351

The incidence and nature of surgical adverse events in Colorado and Utah in 1992. TOP
Gawande AA, Thomas EJ, Zinner MJ, Brennan TA.
Department of Surgery, Brigham and Women's Hospital, Boston, MA 02115, USA.
Surgery 1999 Jul;126(1):66-75
BACKGROUND: Despite more than three decades of research on iatrogenesis, surgical adverse events have not been subjected to detailed study to identify their characteristics. This information could be invaluable, however, for guiding quality assurance and research efforts aimed at reducing the occurrence of surgical adverse events. Thus we conducted a retrospective chart review of 15,000 randomly selected admissions to Colorado and Utah hospitals during 1992 to identify and analyze these events.
METHODS: We selected a representative sample of hospitals from Utah and Colorado and then randomly sampled 15,000 nonpsychiatric discharges from 1992. With use of a 2-stage record-review process modeled on previous adverse event studies, we estimated the incidence, morbidity, and preventability of surgical adverse events that caused death, disability at the time of discharge, or prolonged hospital stay. We characterized their distribution by type of injury and by physician specialty and determined incidence rates by procedure.
RESULTS: Adverse events were no more likely in surgical care than in nonsurgical care. Nonetheless, 66% of all adverse events were surgical, and the annual incidence among hospitalized patients who underwent an operation or child delivery was 3.0% (confidence interval 2.7% to 3.4%). Among surgical adverse events 54% (confidence interval 48.9% to 58.9%) were preventable. We identified 12 common operations with significantly elevated adverse event incidence rates that ranged from 4.4% for hysterectomy (confidence interval 2.9% to 6.8%) to 18.9% for abdominal aortic aneurysm repair (confidence interval 8.3% to 37.5%). Eight operations also carried a significantly higher risk of a preventable adverse event: lower extremity bypass graft (11.0%), abdominal aortic aneurysm repair (8.1%), colon resection (5.9%), coronary artery bypass graft/cardiac valve surgery (4.7%), transurethral resection of the prostate or of a bladder tumor (3.9%), cholecystectomy (3.0%), hysterectomy (2.8%), and appendectomy (1.5%). Among all surgical adverse events, 5.6% (confidence interval 3.7% to 8.3%) resulted in death, accounting for 12.2% (confidence interval 6.9% to 21.4%) of all hospital deaths in Utah and Colorado. Technique-related complications, wound infections, and postoperative bleeding produced nearly half of all surgical adverse events.
CONCLUSION: These findings provide direction for research to identify the causes of surgical adverse events and for targeted quality improvement efforts. PMID: 10418594

Costs of medical injuries in Utah and Colorado.
Thomas EJ, Studdert DM, Newhouse JP, Zbar BI, Howard KM, Williams EJ, Brennan TA.
University of Texas-Houston Medical School 77030, USA.
Inquiry 1999 Fall;36(3):255-64
Patient injuries are thought to have a substantial financial impact on the health care system, but recent studies have been limited to estimating the costs of adverse drug events in teaching hospitals. This analysis estimated the costs of all types of patient injuries from a representative sample of hospitals in Utah and Colorado.
We detected 459 adverse events (of which 265 were preventable) by reviewing the medical records of 14,732 randomly selected 1992 discharges from 28 hospitals. The total costs (all results are discounted 1996 dollars) were $661,889,000 for adverse events, and $308,382,000 for preventable adverse events. Health care costs totaled $348,081,000 for all adverse events and $159,245,000 for the preventable adverse events. Fifty-seven percent of the adverse event health care costs, and 46% of the preventable adverse event costs were attributed to outpatient medical care. Surgical complications, adverse drug events, and delayed or incorrect diagnoses and therapies were the most expensive types of adverse events. The costs of adverse events were similar to the national costs of caring for people with HIV/AIDS, and totaled 4.8% of per capita health care expenditures in these states. PMID: 10570659

How Many Medical Errors?.
What Kind?.Not Following Guidelines .Wrong SideSurgery.Reducing Errors.Doctor Discipline