Rate of Preventable Mortality in Hospitalized Patients: a Systematic Review and Meta-analysis.

Background: The number of preventable inpatient deaths in the USA is commonly estimated as between 44,000 and 98,000 deaths annually. Because many inpatient deaths are believed to be preventable, mortality rates are used for quality measures and reimbursement. We aimed to estimate the proportion of inpatient deaths that are preventable.

Methods: A systematic literature search of Medline, Embase, Web of Science, and the Cochrane Library through April 8, 2019, was conducted. We included case series of adult patients who died in the hospital and were reviewed by physicians to determine if the death was preventable. Two reviewers independently performed data extraction and study quality assessment. The proportion of preventable deaths from individual studies was pooled using a random-effects model.

Results: Sixteen studies met inclusion criteria. Eight studies of consecutive or randomly selected cohorts including 12,503 deaths were pooled. The pooled rate of preventable mortality was 3.1% (95% CI 2.2-4.1%). Two studies also reported rates of preventable mortality limited to patients expected to live longer than 3 months, ranging from 0.5 to 1.0%. In the USA, these estimates correspond to approximately 22,165 preventable deaths annually and 7150 deaths for patients with greater than 3-month life expectancy.

Discussion: The number of deaths due to medical error is lower than previously reported and the majority occur in patients with less than 3-month life expectancy. The vast majority of hospital deaths are due to underlying disease. Our results have implications for the use of hospital mortality rates for quality reporting and reimbursement.

Study Registration: PROSPERO registration number CRD42018095140.