OBJECTIVE:To critically review the existing evidence on interventions aimed at reducing errors in health care delivery.DESIGN: Systematic review of randomized trials on behavioral, educational, informational, and management interventions relating to medical errors. Pertinent studies were identified from MEDLINE, EMBASE, the Cochrane Clinical Trials Registry, and communications with experts.SETTING: Both inpatients and outpatients qualified. No age or disease restrictions were set.
MEASUREMENTS:Outcomes were medical errors, including medication, prescription, and diagnostic errors, and excluding preventive medicine errors and simple ordering of redundant tests.
MAIN RESULTS:Thirteen randomized studies qualified for evaluation. The trials varied extensively in their patient populations (mean age, 2 weeks to 83 years), study setting, definition of errors, and interventions. Most studies could not afford masking and rigorous allocation concealment. In 9 of 13 studies, error rates in the control arms were very high (10% to 63%), and large treatment benefits from the studied interventions were demonstrated for the main outcome. Interventions were almost always effective in a sample of 24 nonrandomized studies evaluated for comparison. Actual patient harm from serious errors was rarely recorded.CONCLUSIONS: Medical errors were very frequent in the studies we identified, arising sometimes in more than half of the cases where there is an opportunity for error. Relatively simple interventions may achieve large reductions in error rates. Evidence on reduction of medical errors needs to be better categorized, replicated, and tested in study designs maximizing protection from bias. Emphasis should be placed on serious errors. M edical errors are a common cause of morbidity and mortality in a variety of health care settings. 1±3 Their importance has been increasingly recognized, as reflected in a recent report by the Institute of Medicine that drew widespread public attention. 4,5 It is estimated that in the United States alone, medical errors result in 44,000 to 98,000 unnecessary deaths and approximately 1 million excess injuries each year. 4,6 Extremes of age, complex and/ or urgent care, and prolonged hospital stay are associated with more errors, but significant errors may also occur in the outpatient setting and for patients of all ages. 4,6 Despite the increasing recognition of the importance of this phenomenon, there is limited knowledge of which interventions may be used to effectively reduce the incidence and impact of errors on medical care. There is optimism that both simple behavioral interventions, system approaches, and information technology-based approaches may alter the incidence and consequences of medical errors. 5,7 However, much of the data pertaining to medical error have been generated using epidemiologic observational studies or intervention studies with before-after comparisons. Randomized evidence has not been carefully scrutinized.In the present systematic review, we undertook to retrieve and crit...