22.7% of Adverse Events During Hospital Admission Are Preventable

A recent study published in the New England Journal of Medicine determined that 22.7% of adverse events during hospital admission were preventable. Researchers in the publication designed their investigation around the 1991 Harvard Medical Practice Study results, which determined that adverse events during hospitalization are a significant concern for patients and patient care.

In the retrospective cohort study, researchers collected data from 11 hospitals in Massachusetts in 2018. They analyzed the frequency, preventability, and severity of patient harm due to adverse events during hospitalization. Adverse event frequency was calculated based on a review of medical records. In addition to tallying frequency, investigators trained nurses and physicians to review patients’ medical records to confirm an adverse event and determine its severity and preventability.

At the study’s close, researchers gathered data from 2809 admissions in Massachusetts. Approximately 23.6% of admitted patients experienced one or more adverse events, meaning that over 650 patients experienced one or more.

Across this sample, the total number of adverse events was 978. Of the total number of adverse events, approximately 222 were preventable. Another 316 events were ranked serious or higher on the severity scale, leading to a long or significant intervention or recovery.

The 222 preventable adverse effects were found among 191 admissions, meaning that 6.8% of all entries experienced a preventable negative effect. The most common adverse effects were due to adverse drug events, accounting for 39% of all adverse effects. Surgical or procedural and patient care events accounted for 30.4% and 15%, respectively. Finally, healthcare-associated infections contributed to 11.9% of adverse events during hospital admissions.

Researchers in the publication concluded, “Adverse events were identified in nearly one in four admissions, and approximately one-fourth of the events were preventable. These findings underscore the importance of patient safety and the need for continuous improvement.”

The results of this study echo the results of multiple other studies noting that the rate of preventable death across the United States is high. A recent report by the HHS noted that approximately 7.4 million patients are misdiagnosed in US emergency departments yearly. If a patient is admitted, these misdiagnoses may contribute to preventable adverse events during hospitalization.

Regardless of the contributing factors, it is clear that additional research must be done on adverse events during hospitalization. Future research may consider examining patient demographics to understand whether specific patient populations are more heavily impacted.