Prevention of non-ventilator-associated hospital-acquired pneumonia in Switzerland: a type 2 hybrid effectiveness-implementation trial

Abstract

Background: Non-ventilator-associated hospital-acquired pneumonia (nvHAP) is a frequent, but under-researched infection. We aimed to simultaneously test an nvHAP prevention intervention and a multifaceted implementation strategy.

Methods: In this single-centre, type 2 hybrid effectiveness-implementation study, all patients of nine surgical and medical departments at the University Hospital Zurich, Switzerland, were included and surveyed over three study periods: baseline (14-33 months, depending on department), implementation (2 months), and intervention (3-22 months, depending on department). The five-measure nvHAP prevention bundle consisted of oral care, dysphagia screening and management, mobilisation, discontinuation of non-indicated proton-pump inhibitors, and respiratory therapy. The implementation strategy comprised department-level implementation teams who conducted and locally adapted the core strategies of education, training, and changing infrastructure. Intervention effectiveness on the primary outcome measure of nvHAP incidence rate was quantified using a generalised estimating equation method in a Poisson regression model, with hospital departments as clusters. Implementation success scores and determinants were derived longitudinally through semistructured interviews with health-care workers. This trial is registered with ClinicalTrials.gov (NCT03361085).

Findings: Between Jan 1, 2017, and Feb 29, 2020, 451 nvHAP cases occurred during 361 947 patient-days. nvHAP incidence rate was 1·42 (95% CI 1·27-1·58) per 1000 patient-days in the baseline period and 0·90 (95% CI 0·73-1·10) cases per 1000 patient-days in the intervention period. The intervention-to-baseline nvHAP incidence rate ratio, adjusted for department and seasonality, was 0·69 (95% CI 0·52-0·91; p=0·0084). Implementation success scores correlated with lower nvHAP rate ratios (Pearson correlation -0·71, p=0·034). Determinants of implementation success were positive core business alignment, high perceived nvHAP risk, architectural characteristics promoting physical proximity of health-care staff, and favourable key individual traits.

Interpretation: The prevention bundle led to a reduction of nvHAP. Knowledge of the determinants of implementation success might help in upscaling nvHAP prevention.

Funding: Swiss Federal Office of Public Health.