Dynamics of HPV vaccination initiation in Flanders (Belgium) 2007-2009: a Cox regression model

Abstract

BackgroundWe investigated dynamic patterns and predictors of HPV vaccination initiation in Flanders (Belgium) by girls aged 12 to 18, between 2007 and 2009, the period immediately after the introduction of the HPV vaccines on the Belgian market. During this period the initiative for vaccination was taken by the girl, her family or the general practitioner/pediatrician/gynecologist.MethodsWe used a Cox regression model with time constant and time varying predictors to model hazard rates of HPV vaccination initiation. The sample existed of 117,151 female members of the National Alliance of Christian Mutualities, the largest sickness fund in Flanders.ResultsThe study showed that the hazard of HPV vaccination initiation was higher (1) for older girls, (2) for girls with a more favorable socio-economic background, (3) under more generous reimbursement regimes (with this effect being more pronounced for girls with weak socioeconomic backgrounds), (4) for girls that were informed personally about the reimbursement rules.ConclusionsWhen the initiative for HPV vaccination lies with the girls, their families or the physicians (no organized setting) the uptake of the vaccines is affected by both individual and organizational factors.

Changing Inequalities in Cervical Cancer: Modeling the Impact of Vaccine Uptake, Vaccine Herd Effects, and Cervical Cancer Screening in the Post-Vaccination Era

“…For example, in England, a survey reported a three-dose vaccine uptake of 72% in white women and of 55% in black women ages 13 to 19 (70). In Belgium, 43% of women 13 to 18 from the lowest median income quintile neighborhoods compared with 57% of women from the highest median income quintile neighborhoods had initiated HPV vaccination (22). HPV vaccination programs vary in terms of targeted ages; however, it is unlikely that this would substantially affect conclusions given programs generally target individuals before their sexual debut.…”

“…However, current evidence suggests that in many settings, the sociodemographic determinants of HPV vaccine uptake are similar to those of cervical cancer screening participation. For example, lower HPV vaccine uptake has been reported for ethnic/racial minorities (19,20) and for children of parents with low education level (21) and low household income or economic status (19,(21)(22)(23). These inequalities in vaccine uptake are more often reported for settings with opportunistic or clinic-based vaccine delivery rather than school-based delivery, though unequal vaccine initiation and/or completion is sometimes reported for school-based delivery as well (20,24,25).…”

Vaccine Marketing

“…HPV vaccination initiation was higher for girls with more generous reimbursement regimes, and for girls that were informed personally about the reimbursement rules (Lefevere et al 2011 ).…”

Factors Influencing Infant and Adolescent Vaccine Uptake in Flanders, Belgium

“…The second series of studies [5,6] [2], N = 127 854 in [3]) and living in 146 Flanders were selected from the membership files of the NACM. Initiation of HPV 147 vaccination between January 2007 and June 2009 varied between 20 and 80 % 148 depending on the year of birth (age) of the girls.…”

“…The accurate representation of population 76 heterogeneity is one of the greatest challenges of epidemic modeling. While 77 substantial progress has been made over the years with the introduction of different 78 mixing functions [29] and mixing matrices [2] for compartmental models, they are 79 still far from achieving a good approximation to real world scenarios. In recent 80 years, new approaches that incorporate more realistic contact structures have been 81 developed to allow for nonrandom interactions among populations [4,22,48,54].…”