Factors associated with human papillomavirus vaccination completion on a catch-up schedule

"Catch-up vaccination" is vaccination outside of the recommended schedule and may occur between 13 and 26 years of age for human papillomavirus vaccines. We aimed to characterize those adolescents and young women who were most likely to complete the three-vaccine series on a catch-up schedule.

We performed a retrospective review of adolescents and young women aged 13-26 years who initiated human papillomavirus vaccination between January 2007 and April 2009 and followed them through April 2010 for vaccine completion (n=310). Completion was defined as receipt of three doses of the human papillomavirus vaccine. We used log binomial regression to investigate characteristics associated with vaccine completion. The main exposure was pregnancy occurring within 1 year of initiating the series. Other exposure variables included age, race, insurance, and clinical site.

Fifty-six percent of participants completed the vaccine series with a mean follow-up of 2 years. After adjusting for age and site of vaccination, those who became pregnant (n=31) were significantly less likely than those who did not to complete the series (22.6% compared with 59.9%, respectively, adjusted relative risk 0.42, 95% confidence interval [CI] 0.21-0.81). Race or ethnicity was also independently associated with completion, with black patients having the lowest completion rate (48% compared with 72.1% among white patients, adjusted relative risk 0.71, 95% CI 0.54-0.91).

Human papillomavirus vaccination completion is low among adolescents and females receiving vaccination on a catch-up schedule. Those who become pregnant may not resume the series after pregnancy. Vaccine initiation is an opportunity for contraceptive provision for adolescents and young women.

: II.