Résumé
Background and aims: Seasonal influenza vaccine (SIV) is recommended in France for people aged 65 + and those with risk factors, including diabetes. The French Health Insurance Fund (NHIF) sends them a voucher to get a free vaccine. SIV uptake (SIVU) remains below the 75% target and has progessively decreased since the 2009 pandemic. We aimed to identify SIVU temporal trajectories (SIVU-T) over a 10-year period and to describe their correlates among patients with diabetes.Materials and methods: We identified 17,259 persons with diabetes in 2006 among a representative sample of French NHIF beneficiaries. We followed them until 3025, using SIV reimbursement claims and group-based trajectory modeling to identify SIVU-T and drug reimbursement claims to assess diabetes severity and comorbidity status. A multinomial logistic regression allowed us to study characteristics associated with SIVU-T.Results: Fig 1 shows the 6 SIVU-T: 1) "never" T (32%): people with quasi null SIVU probabilities (≤5%) ; 2) « late increasing » T (4%): SIVU probability varying from ≤10% before 2011/12 to 85% in 2015/16; 3) “early increasing” T (8%): probability varying from ≤10% in 2006/07 to ≥80% starting in 2009/10; 4) “regular” T (33%): probability always ≥95%; 5) “progressively non-vaccinated” T (14%): probability decreasing from 90% in 2006/07 to 20% in 2015/16; 6) “post-pandemic decreasing” T (9%): probability decreasing right after the 2009/10 season. Compared to “never” T, all other had poorer health (severe diabetes, high comorbidity score). The “late increasing” T were more likely to have newly received NHIF vouchers and changed general practitioners (GPs) during follow-up, and the “early increasing” T more likely to have newly received NHIF vouchers and to have been hospitalized for influenza-like illness during follow-up. The “regular” T were less likely to have been hospitalized due to diabetes. The “progressively non-vaccinated” T were older (80 ± 7 years at inclusion versus 65 ± 14 in the study population). The “post-pandemic decreasing” T were more often women, more likely to have been hospitalized for influenza-like illness, and to have changed GP during follow-up.Conclusion: SIVU behavior was mostly stable over the study period. The "never" T were healthier and may feel less vulnerable to influenza. The "progressively non-vaccinated" T may reflect doubts about benefits of SIV in older subjetcs. The "post-pandemic decreasing" T may have lost confidence in SIV after the 2009 pandemic vaccination campaign controversies in France. Our data suggest that sending free vouchers might trigger behavioral change, and that hospitalization for influenza-like illness or change of GP may represent key opportunities to foster or prevent behavioral changes towards SIV. These results should help stakeholders to adapt public health interventions to specific subgroups.