Panagioti and colleagues, writing in the BMJ, conducted a meta-analysis of 70 studies measuring adverse events. These studies included over a third-of-a-million patients.[1] They found that about half of all harms are preventable; about one-fifth of preventable harms are serious or life-threatening; and intensive care and surgery are the highest risk specialties. These estimates have remained stable over decades.

The great majority of studies are hospital-based and rely on reviews of case-notes. This study does not give much information on reliability, a topic that has been thoroughly reviewed in our ARC.[2] Nevertheless, the study does mention the probability that many harms are not picked up in case-notes. Some people have been investigating the possibility of combining case-note review with patient accounts of their experiences. While citing one ARC WM authored study, this review does not mention some of our work on gradually improving harm rates over time.[3]

Richard Lilford, ARC WM Director

References:

1. Panagioti M, Khan K, Keers RN, et al. Prevalence, severity, and nature of preventable patient harm across medical care settings: systematic review and meta-analysis. BMJ. 2019; 366: I4185.
2. Manaseki-Holland S, Lilford RJ, Te AP, et al. Ranking Hospitals Based on Preventable Hospital Death Rates: A Systematic Review With Implications for Both Direct Measurement and Indirect Measurement Through Standardized Mortality Rates. Milbank Quart. 2019.
3. Benning A, Dixon-Woods M, Nwulu U, et al. Multiple component patient safety intervention in English hospitals: controlled evaluation of second phase. BMJ. 2011; 342: d199.