Volume 56 | Number S3 | December 2021

Abstract List

Rocco Friebel PhD, Cornelia PD, Dr. rer. oec, Laia Maynou PhD


To estimate the risk of an avoidable adverse event for high‐need patients in England and Germany and the causal impact that has on outcomes.

Data Sources

We use administrative, secondary data for all hospital inpatients in 2018. Patient records for the English National Health Service are provided by the Hospital Episode Statistics database and for the German health care system accessed through the Research Data Center of the Federal Statistical Office.

Study Design

We calculated rates of three hospital‐acquired adverse events and their causal impact on mortality and length of stay through propensity score matching and estimation of average treatment effects.

Data Collection/Extraction Methods

Patients were identified based on diagnoses codes and translated Patient Safety Indicators developed by the Agency for Healthcare Research and Quality.

Principal Findings

For the average hospital stay, the risk of an adverse event was 5.37% in the English National Health Service and 3.26% in the German health care system. High‐need patients are more likely to experience an adverse event, driven by hospital‐acquired infections (2.06%–4.45%), adverse drug reactions (2.37%–2.49%), and pressure ulcers (2.25%–0.45%). Adverse event risk is particularly high for patients with advancing illnesses (10.50%–27.11%) and the frail elderly (17.75%–28.19%). Compared to the counterfactual, high‐need patients with an adverse event are more likely to die during their hospital stay and experience a longer length of stay.


High‐need patients are particularly vulnerable with an adverse event risking further deterioration of health status and adding resource use. Our results indicate the need to assess the costs and benefits of a hospital stay, particularly when care could be provided in settings considered less hazardous.