33JDM GIRLS' PREFERENCES FOR HPV-VACCINATIONS: A DISCRETE CHOICE EXPERIMENT

Tuesday, October 20, 2009
Grand Ballroom, Salons 1 & 2 (Renaissance Hollywood Hotel)
Esther W. de Bekker-Grob, MSc, Robine Hofman, MSc, Marjolein van Ballegooijen, MD, PhD, Hein Raat, MD, PhD and Ida J. Korfage, PhD, Erasmus MC - University Medical Center Rotterdam, Rotterdam, Netherlands

Purpose: This year HPV-vaccinations were added to the Dutch National Immunization Program for 12 year old girls.  A catch up program was organized for girls aged 13 to 16 years. However, determinants of girls’ acceptance of the new vaccine are unknown. We aimed to elicit the relative weight that girls place on various aspects of HPV-vaccination.

Method: A discrete choice experiment (DCE) was administered to girls aged 12 to 16 years at secondary schools in different areas in the Netherlands. Girls had to choose between vaccination profiles that differed in five characteristics: level of protection against cervical cancer, protection duration, serious side effects (e.g. hospitalization), mild side effects (e.g. nausea), and age of vaccination. The relative importance of the vaccine attributes and the trade-offs that girls were willing to make between these attributes were estimated using multinomial logistic regression analysis. Mediums of how respondents wanted more information about the HPV-vaccine were also investigated.

Result: Preliminary results of 72 girls were available for analysis; response rate 75%. All vaccine characteristics that were assessed proved to be important for girls’ choices (p<0.05). Respondents required an additional protection against cervical cancer of 10% for vaccination at age 9 years instead of age 12 years, 17% in order to expose themselves to an 1 per 100.000 risk increase in serious side effects and to a 24% risk increase in mild side effects, and 52% to accept a protection of six years instead of lifetime protection. There was no significant difference in preference for vaccination at age 12 years or 14 years. Three quarters of the girls wanted more information about the vaccine and preferred to be informed through their parents, their general practitioner or their school.

Conclusion: Preliminary results showed that especially protection against cervical cancer, protection duration and serious side effects influenced HPV-vaccination preferences. Data on these vaccine characteristics are not yet available, since so far follow-up data on HPV vaccinated women lasted for six years. It is therefore important to inform girls well about new developments regarding these vaccine characteristics through the preferred mediums.  

Candidate for the Lee B. Lusted Student Prize Competition