Determinants of human papillomavirus vaccination uptake among adolescent girls: A theory-based longitudinal study among Hong Kong Chinese parents.

Human papillomavirus (HPV) vaccination uptake among Chinese adolescent girls remains extremely low. This two-year longitudinal study examined theoretical predictors of adolescent girls' HPV vaccination uptake using an extended Theory of Planned Behaviour (TPB). Between February and November 2014, a random sample of 1996 (response rate 60%) Hong Kong Chinese parents of 12- to 17-year-old HPV unvaccinated girls completed baseline telephone interviews assessing attitudes and intention towards HPV vaccination. Six and 12months later 1255 and 979 parents reported their daughters' HPV vaccination status, respectively. Structural equation modelling tested data fit to an TPB-derived hypothesized model of baseline factors predicting parental decisionmaking for adolescent girls' subsequent HPV vaccination uptake. Overall, at 1-year follow-up, only 9.8% (97/988) of participants' daughters received at least one dose of HPV vaccines. Descriptive norms (β=0.28), perceived greater benefits of HPV vaccination (β=0.17), anticipated affective consequences (β=0.32), and attitude to general optional vaccines (β=0.09) were associated with parental vaccination intention. Barriers to HPV vaccination (β=-0.31), descriptive norms (β=0.17), perceived self-efficacy (β=0.73), and vaccination intention (β=0.11) were associated with vaccination planning. Vaccination intention (β=0.31) and planning (β=0.18) modestly predicted vaccination uptake. The lack of government-organized HPV vaccination programme may result in persistent low HPV vaccination uptake and many young women may remain vulnerable to future cervical cancer risk in Hong Kong.