Patient safety

Selected bibliography supporting the ten essential objectives for safe surgery

Background reading

Brennan, T. A., L. L. Leape, et al. (1991). "Incidence of adverse events and negligence in hospitalized patients. Results of the Harvard Medical Practice Study I." N Engl J Med 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.

Debas, H., R. Gosselin, et al. (2006). “Surgery”. Disease Control Priorities in Developing Countries, 2nd ed. Disease Control Priorities Project., The International Bank for Reconstruction and Development / The World Bank.

Gawande, A. A., E. J. Thomas, et al. (1999). "The incidence and nature of surgical adverse events in Colorado and Utah in 1992." Surgery 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.

Kable, A. K., R. W. Gibberd, et al. (2002). "Adverse events in surgical patients in Australia." Int J Qual Health Care 14(4): 269-76.

  • OBJECTIVE: To determine the adverse event (AE) rate for surgical patients in Australia.
  • DESIGN: A two-stage retrospective medical record review was conducted to determine the occurrence of AEs in hospital admissions. Medical records were screened for 18 criteria and positive records were reviewed by two medical officers using a structured questionnaire.
  • SETTING: Admissions in 1992 to 28 randomly selected hospitals in Australia.
  • STUDY PARTICIPANTS: Five hundred and twenty eligible admissions were randomly selected from in-patient database in each hospital. A total of 14,179 medical records were reviewed, with 8747 medical and 5432 surgical admissions.
  • MAIN OUTCOME MEASURES: Measures included the rate of AEs in surgical and medical admissions, the proportion resulting in permanent disability and death, the proportion determined to be highly preventable, and the identification of risk factors associated with AEs.
  • RESULTS: The AE rate for surgical admissions was 21.9%. Disability that was resolved within 12 months occurred in 83%, 13% had permanent disability, and 4% resulted in death. Reviewers found that 48% of AEs were highly preventable. The risk of an AE depended on the procedure and increased with age and length of stay.
  • CONCLUSION: The high AE rate for surgical procedures supports the need for monitoring and intervention strategies. The 18 screening criteria provide a tool to identify admissions with a greater risk of a surgical AE. Risk factors for an AE were age and procedure, and these should be assessed prior to surgery. Prophylactic interventions for infection and deep vein thrombosis could reduce the occurrence of AEs in hospitals.

Leape, L., T. Brennan, et al. (1991). "The nature of adverse events in hospitalized patients: The results of the Harvard Medical Practice Study II." New England Journal of Medicine 324: 377-384.

  • 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.

Pronovost, P., D. Needham, et al. (2006). "An intervention to decrease catheter-related bloodstream infections in the ICU." N Engl J Med 355(26): 2725-32.

  • BACKGROUND: Catheter-related bloodstream infections occurring in the intensive care unit (ICU) are common, costly, and potentially lethal.
  • METHODS: We conducted a collaborative cohort study predominantly in ICUs in Michigan. An evidence-based intervention was used to reduce the incidence of catheter-related bloodstream infections. Multilevel Poisson regression modeling was used to compare infection rates before, during, and up to 18 months after implementation of the study intervention. Rates of infection per 1000 catheter-days were measured at 3-month intervals, according to the guidelines of the National Nosocomial Infections Surveillance System.
  • RESULTS: A total of 108 ICUs agreed to participate in the study, and 103 reported data. The analysis included 1981 ICU-months of data and 375,757 catheter-days. The median rate of catheter-related bloodstream infection per 1000 catheter-days decreased from 2.7 infections at baseline to 0 at 3 months after implementation of the study intervention (P< or =0.002), and the mean rate per 1000 catheter-days decreased from 7.7 at baseline to 1.4 at 16 to 18 months of follow-up (P<0.002). The regression model showed a significant decrease in infection rates from baseline, with incidence-rate ratios continuously decreasing from 0.62 (95% confidence interval [CI], 0.47 to 0.81) at 0 to 3 months after implementation of the intervention to 0.34 (95% CI, 0.23 to 0.50) at 16 to 18 months.
  • CONCLUSIONS: An evidence-based intervention resulted in a large and sustained reduction (up to 66%) in rates of catheter-related bloodstream infection that was maintained throughout the 18-month study period.

Reason, J. (1992). Human Error. Cambridge, Mass, Cambridge University Press.

Weiser, T., S. Regenbogen, et al. "An estimation of the global volume of surgery." The Lancet (accepted for publication).

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