Background: Diagnostic error is commonly defined as a missed or delayed diagnosis and has been described as among the most important patient safety hazards. Diagnostic errors also account for the largest category of medical malpractice high severity claims and total payouts. Despite a large literature on the incidence of inpatient adverse events, no systematic review has attempted to estimate the prevalence and nature of diagnostic errors in hospitalized patients.
Methods: A systematic literature search was conducted using MEDLINE, Embase, Web of Science, and the Cochrane library from database inception through July 9, 2019. We included all studies of hospitalized adult patients that used physician review of case series of admissions and reported the frequency of diagnostic adverse events. Two reviewers independently screened studies for inclusion, extracted study characteristics and assessed risk of bias using the Joanna Briggs Institute Checklist for Prevalence Studies. Diagnostic error rates were pooled using a random-effects model. Between-study heterogeneity was estimated using the I² statistic. Subgroup analysis and meta-regression were performed using study level variables including geographic location, exclusion criteria, definitions of adverse event and diagnostic error, and study risk of bias. Statistical analysis was performed using metaprop, metareg and metafunnel commands in Stata/MP, version 15.1 (StataCorp, College Station, Texas).
Results: Twenty-two studies including 80,026 patients and 760 diagnostic errors from consecutive or randomly selected cohorts were pooled. The pooled rate was 0.7% (95% CI 0.5-1.1%). Of the 136 diagnostic errors that were described in detail, a wide range of diseases were missed, the most common being malignancy (n=15, 11%), pulmonary embolism (n=13, 9.6%), aortic aneurysm (n=5, 3.7%), congestive heart failure (n=5, 3.7%), urinary tract infection (n=5, 3.7%), and gastrointestinal perforation (n=5, 3.7%). In the United States, these estimates correspond to approximately 249,900 diagnostic errors yearly.
Conclusions: Based on physician review, at least 0.7% of admissions involve a diagnostic error. A wide range of diseases are missed, including many common diseases. Fourteen diagnoses account for more than half of all diagnostic errors. This is fundamental information for patients and physicians who are interested in improving the diagnostic process.
