Predictors of Human Papillomavirus Vaccine Completion Among Female and Male Vaccine Initiators in Family Planning Centers.

Objectives: We estimated human papillomavirus (HPV) vaccine series completion and examined predictors of completion among adolescents and young adults in a large family planning network.
Methods: Our retrospective cohort study of vaccine completion within 12 months and time to completion used electronic health record data from 119 Planned Parenthood health centers in 11 US states for 9648 patients who initiated HPV vaccination between January 2011 and January 2013.
Results: Among vaccine initiators, 29% completed the series within 12 months. Patients who were male, younger than 22 years, or non-Hispanic Black or who had public insurance were less likely to complete within 12 months and completed more slowly than their counterparts. Gender appeared to modify the effect of public versus private insurance on completion (adjusted hazard ratio = 0.76 for women and 0.95 for men; relative excess risk due to interaction = 0.41; 95% confidence interval = 0.09, 0.73).
Conclusions: Completion was low yet similar to previous studies conducted in safety net settings.