Trajectories of seasonal influenza vaccine uptake among French people with diabetes: a nationwide retrospective cohort study, 2006-2015.

ABSTRACT

BACKGROUND: Annual seasonal influenza vaccination (SIV) is recommended for people with diabetes, but their SIV rates remain far below public health targets. We aimed to identify temporal trajectories of SIV uptake over a 10-year period among French people with diabetes and describe their clinical characteristics. METHODS: We identified patients with diabetes in 2006 among a permanent, representative sample of beneficiaries of the French National Health Insurance Fund. We followed them up over 10 seasons (2005/06-2015/16), using SIV reimbursement claims and group-based trajectory modelling to identify SIV trajectories and to study sociodemographic, clinical, and healthcare utilization characteristics associated with the trajectories. RESULTS: We identified six trajectories. Of the 15,766 patients included in the model, 4344 (28%) belonged to the "continuously vaccinated" trajectory and 4728 (30%) to the "never vaccinated" one. Two other trajectories showed a "progressive decrease" (2832, 18%) or sharp "postpandemic decrease" (1627, 10%) in uptake. The last two trajectories (totalling 2235 patients, 14%) showed an early or delayed "increase" in uptake. Compared to "continuously vaccinated" patients, those in the "progressively decreasing" trajectory were older and those in all other trajectories were younger with fewer comorbidities at inclusion. Worsening diabetes and comorbidities during follow-up were associated with the "increasing" trajectories. CONCLUSIONS: Most patients with diabetes had been continuously vaccinated or never vaccinated and thus had stable SIV behaviours. Others adopted or abandoned SIV. These behaviour shifts might be due to increasing age, health events, or contextual factors (e.g., controversies about vaccine safety or efficacy). Healthcare professionals and stakeholders should develop tailored strategies that take each group's specificities into account.