Effectiveness of interventions to increase healthcare workers’ adherence to vaccination against vaccine-preventable diseases: a systematic review and meta-analysis, 1993 to 2022

Abstract

Background Vaccination adherence among healthcare workers (HCWs) is fundamental for the prevention of vaccine-preventable diseases (VPDs) in healthcare. This safeguards HCWs' well-being, prevents transmission of infections to vulnerable patients and contributes to public health. Aim This systematic review and meta-analysis aimed to describe interventions meant to increase HCWs’ adherence to vaccination and estimate the effectiveness of these interventions. Methods We searched literature in eight databases and performed manual searches in relevant journals and the reference lists of retrieved articles. The study population included any HCW with potential occupational exposure to VPDs. We included experimental and quasi-experimental studies presenting interventions aimed at increasing HCWs’ adherence to vaccination against VPDs. The post-intervention vaccination adherence rate was set as the main outcome. We included the effect of interventions in the random-effects and subgroup meta-analyses. Results The systematic review considered 48 studies on influenza and Tdap vaccination from database and manual searches, and 43 were meta-analysed. A statistically significant, positive effect was seen in multi-component interventions in randomised controlled trials (relative risk (RR) = 1.37; 95% CI: 1.13–1.66) and in observational studies (RR = 1.43; 95% CI: 1.29–1.58). Vaccination adherence rate was higher in community care facilities (RR = 1.58; 95% CI: 1.49–1.68) than in hospitals (RR = 1.24; 95% CI: 0.76-2.05). Conclusion Interventions aimed at increasing HCWs’ adherence to vaccination against VPDs are effective, especially multi-component ones. Future research should determine the most effective framework of interventions for each setting, using appropriate study design for their evaluation, and should compare intervention components to understand their contribution to the effectiveness.