Background: In Spain, girls and women are vaccinated against human papillomavirus (HPV) in the primary care setting, according to a national vaccination program. Vaccination is voluntary and the cost is covered by the public health system.
Objectives: The aim of the study was to estimate the incidence and patterns of HPV vaccination amongst girls in Spain.
Methods: A cohort study was performed using the information recorded in the Spanish Primary Care Database for Pharmacoepidemiological Research (BIFAP) from 7.4 million patients from eight Spanish regions, between 2001 and 2013 (56% of the regional population). Data available in BIFAP include patient age, sex, lifestyle factors, clinical events, specialist referrals, prescriptions, and vaccinations as recorded by the primary care physician (PCP) or administering nurse. The study cohort comprised all girls aged 11-18 years registered in BIFAP between 1 January 2007 and 31 December 2013 who had at least 1 year of clinical record information with their PCP (inclusion criteria). The date the inclusion criteria were met was designated as the start date of the study cohort contribution. In order to estimate the incidence of HPV vaccination, girls forming the study cohort were followed from start date until there was a recorded HPV vaccination, they reached 19 years of age or died, the end of available information, or 31 December 2013. The person-time of all patients forming the study cohort was taken into account in the incidence estimations. The cumulative incidence (CuIn) of vaccination by birth cohort, year and region was estimated using life-tables (proportion of vaccination by intervals in which the denominator is the initial population corrected for losses).
Results: Out of 273,098 girls forming the study population, 81,461 were vaccinated during 2007-2013. Age ranged from 12 to 14 years at first dose in 86.0% of vaccinated girls; 54.1% received a quadrivalent vaccine, 21.9% a bivalent vaccine, and 24.0% an unknown type. Out of the vaccinated population, 87.9% received three doses, 8.2% two and 3.9% one dose, at a maximum of 7 years of follow-up. By calendar year and region, the CuIn reached 70.0-95.8% for birth cohorts between 1993 and 1999, 28.6-99.0% for births cohorts between 1990 and 1992, and exceptionally, 70.6-99.8% for births cohorts between 2000 and 2002 in three regions.
Conclusions: According to BIFAP primary care data, a high incidence of vaccination among girls aged 13-15 years was observed. Vaccination among younger and older girls was less common although they reached high incidence in those regions that included girls aged 11-18 years in mass programs. Most vaccination patterns adjusted to a three-dose regimen, as recommended.