Abstract
Abstract Background Pneumococcal vaccination rates are critically low among high-risk patients, particularly those with heart failure (HF), who face increased risk of severe infections and complications. There is limited evidence on the effectiveness of simple interventions to improve vaccination uptake in this population. Objectives A prospective interventional trial was designed to evaluate the impact of an incentive campaign carried out by the French health insurance. Methods This study was an open-label pragmatic cluster randomized controlled trial involving general practitioners (GPs) and their related patients with chronic HF in a French region, identified through the regional health insurance database. Data were routinely collected using this database to conduct the study. HF patients were assigned to intervention or control groups based on the randomized allocation of their treating GPs. In the intervention group, both GPs and their patients received two vaccination incentive letters, whereas the control group was only observed. Vaccines were provided at no cost under the French vaccination program. The primary endpoint was the pneumococcal vaccination rate at one year. The secondary objective aimed to identify factors associated with vaccine uptake. Results 3952 GPs and 12 285 corresponding patients with HF were included between Mar 23, 2023, and Mar 23, 2024. The pneumococcal vaccination rate at one year was 35% in the intervention group (n = 6140) versus 3.5% in the control group (n = 5937). Multivariable analyses showed a 15-fold higher rate of vaccination in patients receiving the intervention. The vaccination rate increased with male patients, female GP, and previous influenza vaccination but decreased in younger (<70 years) and older patient age (>85 years). Discussion This randomized study demonstrated the effectiveness of a mail-in promotion to sustainably increase pneumococcal vaccination coverage in a frail high-risk population.