Predictors of Human Papillomavirus Vaccine Follow-Through Among Privately Insured US Patients

Objectives. To assess predictors of timely human papillomavirus (HPV) vaccine follow-through among privately insured individuals initiating the 3-dose series.Methods. Using MarketScan Commercial claims data, we identified 1 332 217 privately insured US individuals aged 9 to 26 years who initiated the bivalent or quadrivalent HPV vaccine series from 2006 to 2014, with follow-up data extending through 2015. The study outcome was receipt of third HPV dose within 12 months of the first, compared by year of initiation. Control variables were age, region, insurance plan type, provider type, and seasonal influenza vaccination.Results. Timely HPV vaccine follow-through fell over time. The trend was especially pronounced for females (from 67% in 2006 to 38% in 2014), but was also present for males (from 36% in 2011 to 33% in 2014). Similar patterns were present when we controlled for patient and provider characteristics or used alternative definitions of follow-through. Other positive predictors of timely follow-t...