Dynamics of HPV vaccination initiation in Flanders (Belgium) 2007-2009: a Cox regression model
1 Herman Deleeck Centre for Social Policy, Antwerp University, St Jacobstraat 2, 2000 Antwerpen, Belgium
2 Research Foundation Flanders, Egmontstraat 5, 1000 Brussel, Belgium
3 Centre for Statistics (CENSTAT), Hasselt University, Agoralaan, Building D, 3590 Diepenbeek, Belgium
4 Centre for Health Economics Research and Modeling Infectious Diseases (CHERMID), Antwerp University, Universiteitsplein 1, 2610 Wilrijk, Belgium
5 Medical Management Department, National Alliance of Christian Mutualities, Haachtsesteenweg 579, 1031 Brussel, Belgium
6 Department of Occupational, Environmental and Insurance Medicine, Catholic University Leuven, Kapucijnenvoer 35/5, 3000 Leuven, Belgium
7 Vaccine and Infectious Diseases Institute (VAXINFECTIO), Antwerp University, Universiteitsplein 1, 2610 Wilrijk, Belgium
8 Centre for the Evaluation of Vaccinations, Antwerp University, Universiteitsplein 1, 2610 Wilrijk, Belgium
BMC Public Health 2011, 11:470 doi:10.1186/1471-2458-11-470Published: 14 June 2011
We 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.
We 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.
The 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.
When 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.