Point Prevalence Rate Useful Only to a Limited Extent

Letters to the Editor Healthcare-Associated Infections and the Use of Antibiotics in German Hospitals by PD Dr. med. Seven Johannes Sam Aghdassi, PD Dr. med. Sonja Hansen, Luis Alberto Peña Diaz, M.Sc., Alexander Gropmann, Selin Saydan, M.Sc., Prof. Dr. med. Christine Geffers, Prof. Dr. med. Petra Gastmeier, Dr. med. Brar Piening, and Dr. rer. medic. Michael Behnke in issue 9/2024

The frequency of adverse events (AE) is often calculated using cross-sectional surveys. The resulting point prevalence rate indicates the proportion of patients suffering from an AE at the same time. According to Aghdassi et al., 3 to 4 out of every 100 patients are simultaneously affected by a healthcare-associated infection (HAI) acquired during hospital stay (in-house HAI) (1). This estimate determines the resource requirements of hospitals. For assessment of patient safety, however, the point prevalence rate is of only limited use; the risk of newly admitted patients to suffer from an AE is more important. This risk can be estimated by the frequency of AE over time, the period prevalence rate. For AE, the period prevalence rate is lower, since increasing length of stay elevates both the risk of an AE and the probability of inclusion in a cross-sectional survey. Probably only 2% to 3% of patients suffer an in-house HAI over a period of a year. The period prevalence rate can be calculated using routine data from hospitals. Unfortunately, not all AE are specified adequately in ICD-10. Moreover, no date is attached to the diagnoses that could be used to trace the origin of an AE. In contrast, ICD-11 takes requirements of patient safety into account (3). Aghdassi et al.’s comparison of 2022 and 2016 is, furthermore, biased by a decrease in length of stay. The conclusion of a stable point prevalence rate is therefore questionable. The presented figures show an increase from 60 to 64 patients with AE per 10 000 bed-days (core group, in-house HAI, not significant). A deterioration in patient safety can consequently not be ruled out. However, the source of the data on length of stay remains unclear. According to the study protocol, no corresponding information was recorded.

DOI: 10.3238/arztebl.m2024.0128

Prof. Dr. med. Jürgen Stausberg

Universität Duisburg-Essen, Universitätsklinikum Essen

Institut für Medizinische Informatik, Biometrie und Epidemiologie (IMIBE)

Conflict of interest statement

The author declares that no conflict of interest exists.

References

1. Aghdassi SJS, Hansen S, Peña Diaz LA, et al.: Healthcare-associated infections and the use of antibiotics in German hospitals—results of the point prevalence survey of 2022 and comparison with earlier findings. Dtsch Arztebl Int 2024; 121: 277–83

2. Stausberg J, Kröger K, Maier I, Niebel W, Schneider S, für das interdisziplinäre Dekubitusprojekt: Häufigkeit des Dekubitus in einem Universitätsklinikum. Kombination von Routinedokumentation und Querschnittstudie. DMW 2005; 130: 2311–5

3. Forster AJ, Chute CG, Pincus HA, Ghali WA: ICD-11: a catalyst for advancing patient safety surveillance globally. BMC Med Inform Decis Mak 2023; 21 (Suppl 6): 383