Purpose: In 2009 the Human Papillomavirus (HPV) vaccine against cervical cancer has been added to the Dutch National Immunization Program for (pre)adolescent girls. Parental consent is not obligatory. In practice parents and girls tend to make shared decisions and preferences for characteristics of the HPV vaccine of both parties will influence uptake. To date similarities and differences between girls’ and parental preferences are unknown. We assessed how characteristics of the HPV vaccine determined uptake intentions in girls and parents, and compared preferences.
Method: A discrete choice experiment (DCE) was conducted among a sample of girls aged 11-16 and among another sample of parents with a daughter aged 10-12. Respondents were asked to choose between hypothetical HPV vaccination programs comprising different levels of four characteristics: degree of protection, protection duration, risk of serious side-effects, and age at which vaccination is offered. A multinomial logit regression model was used to analyze the results.
Result: Response rates were 325/359 (91%) for girls and 307/983 (31%) for parents. In both groups all vaccine characteristics proved to influence preferences for HPV vaccination (p<0.05). Serious side-effects were evaluated more negatively by parents than by girls (p<0.01), while parents had a more positive attitude towards HPV vaccinations at a later age than girls (p<0.05). Girls were willing to trade-off 12% and parents 10% of the protection against cervical cancer to obtain life-time protection instead of 25 years. To get an HPV vaccination at age 12 years instead of 9 years, girls were willing to trade-off 6% and parents 10% of the protection against cervical cancer.
Conclusion: This study showed that parents and even girls were able to make trade-offs using numerical rates. Their trade-offs between the degree of protection against cervical cancer and other characteristics of HPV vaccinations were similar. However, girls evaluated serious side-effects less negatively than parents. Girls may possibly be less able to imagine the seriousness of such side-effects. Parents favored vaccination at a later age than girls did, possibly because parents underestimate their daughter’s age of sexual initiation. Since prevalence of HPV is highest shortly after sexual debut and protection is reduced after HPV infection, parents should be made aware that vaccination is less useful once their daughter has been infected with HPV.
Candidate for the Lee B. Lusted Student Prize Competition