Online Program

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Thursday, January 11
Thu, Jan 11, 11:00 AM - 12:45 PM
Crystal Ballroom E
Difference in Differences (DiD) and Propensity Scores

Human Papillomavirus Vaccine Dose Effectiveness Against Incident Genital Warts in a Cohort of Insured US Females (304282)

Bradley Crane, Kaiser Permanente 
Matthew Daley, Kaiser Permanente 
Susan Hariri, CDC 
Lauri Markowitz, CDC 
Allison Naleway, Kaiser Permanente 
Sophia Newcomer, Kaiser Permanente 
*Megan Schuler, RAND Corporation 
Dennis Tolsma, Kaiser Permanente 
Sheila Weinmann, Kaiser Permanente 

Keywords: HPV, vaccine effectiveness, propensity score

This study examined effectiveness of HPV vaccination by dose number and dose interval against incident genital warts in a cohort of 64,517 women during 2006-2012. Our study population was insured women with varying compliance to the 3 dose HPV vaccine series, providing an ideal effectiveness study. Exposure groups of interest were 0, 1-dose, 2-dose <6 months apart, 2-dose =6 months apart, and 3-dose groups. Propensity score weights were used to balance baseline group differences. To account for latent genital warts before vaccination, 6-month and 12-month buffer periods from last and first vaccine dose, respectively, were applied. Propensity score-weighted incidence rate per 100,000 person-years was 762 among the unvaccinated. Using 6-month and 12-month buffer periods, respectively, incidence rates were 641 and 257 in 1-dose, 760 and 577 in 2-dose (<6 months), 313 and 194 in 2-dose (=6 months), and 199 and 162 in 3-dose vaccines. Vaccine effectiveness was 68% and 76% in 2-dose (=6 months) and 77% and 80% in 3-dose vaccinees compared to unvaccinated. Neither 1-dose nor 2-dose (<6 months) showed significant effectiveness compared to unvaccinated.