# Antimicrobial Stewardship in German non-university hospitals: baseline status and impact of a multifaceted AMS intervention within the prospective ID ROLL OUT study

## TL;DR

This study evaluates antimicrobial stewardship in German non-university hospitals and finds that targeted interventions improve practices, but long-term success requires ongoing staffing.

## Contribution

The study introduces and validates the AMS-GER score, a tool adapted from French guidelines to assess and improve antimicrobial stewardship in German hospitals.

## Key findings

- Baseline antimicrobial stewardship in German non-university hospitals was poor, with a median AMS-GER score of 37%.
- A multifaceted intervention significantly improved the AMS-GER score to 76%, but scores declined after one year without sustained staffing.
- Hospitals with ongoing AMS/ID staffing showed smaller declines in AMS-GER scores compared to those without.

## Abstract

Non-university hospitals are the major provider of inpatient care in Germany, but the extent of antimicrobial stewardship (AMS) activities in this sector is not well known. We aimed to evaluate the implementation of AMS in ten non-university hospitals in Germany.

A pre-existing French score covering key AMS categories (structures, resources and actions) was adapted to the German AMS guidelines and named AMS-GER score. The score was assessed before, during and after the implementation of a bundle of AMS measures. The bundle was implemented as part of the ID ROLL OUT study – a multicentre pre-post interventional study in non-university hospitals in Germany.

At baseline, the median AMS-GER score was 37% (range 20–60%), indicating poor implementation in 9 out of 10 hospitals. The intervention resulted in a significant score improvement to 76% (range: 62–86%, p < 0.001). At the one-year follow-up after the intervention, the AMS-GER score had decreased in all hospitals (median: -13 percentage points (range: 48–80%, p = 0.015)). Hospitals with ongoing full-time AMS/ID staffing (4/10 hospitals) experienced a smaller decrease ( – 13 percentage points) than those without ( – 32 percentage points in 6/10 hospitals).

Routine integration of AMS in a large sample of non-university hospitals in Germany is low but can be significantly improved by targeted interventions. The decline in the AMS-GER score in the follow-up phase—particularly in hospitals lacking ongoing AMS/ID staffing—highlights the need for sustained staffing and systematic benchmarking. In this context, the AMS-GER score offers a structured tool for AMS monitoring in German hospitals.

The online version contains supplementary material available at 10.1007/s15010-025-02658-x.