Tuesday, October 20, 2009
Grand Ballroom, Salons 1 & 2 (Renaissance Hollywood Hotel)
Jane J. Kim, PhD and Sue J. Goldie, MD, MPH, Harvard School of Public Health, Boston, MA
Purpose: Vaccines that target HPV-16,-18 have demonstrated high efficacy against precancerous cervical, vaginal, and vulva lesions among females. Efficacy data in males are limited and efficacy data against other HPV-16,-18 conditions, such as anal, oral, and oro-pharyngeal cancers, are not yet available. Current U.S. recommendations prioritize routine HPV vaccination of girls ages 11-12. We evaluated the cost-effectiveness of including boys in an HPV vaccination program in the U.S. Method: We employed a series of previously-published disease simulation models that include a dynamic model to reflect sexual transmission of HPV-16 and -18 between females and males, and an individual-based microsimulation model to reflect cervical disease associated with all HPV types and detailed screening strategies. Both models were empirically-calibrated to fit to epidemiological data from the U.S., including HPV prevalence and cervical cancer incidence. Incidence-based models were used to estimate the health and economic burden of non-cervical HPV-related diseases for both females and males. Strategies included HPV vaccination of 12-year-old girls and vaccination of 12-year-old girls and boys in the context of current cytology screening. For the base case analysis, we assumed 75% vaccination coverage and 100% lifelong efficacy for both girls and boys. In sensitivity analysis, we explored the impact of gender-specific vaccine efficacy, efficacy against health outcomes not yet observed in clinical trials, duration of vaccine protection, and changes in screening practice. Result: With 75% vaccination coverage and an assumption of complete, lifelong vaccine protection, routine HPV vaccination of 12-year-old girls was generally less than $50,000 per QALY gained, compared with screening alone. Including boys in the routine vaccination program resulted in higher costs and benefits and generally had cost-effectiveness ratios that exceeded $100,000 per QALY, across a range of included HPV-related outcomes, scenarios of cervical cancer screening, and assumptions of vaccine efficacy and duration. Only when all potential health benefits from the vaccine were included under optimistic assumptions of 100% efficacy for both females and males over the lifetime did vaccinating both girls and boys fall below a willingness-to-pay threshold of $100,000 per QALY. Conclusion: Given currently available information, if vaccination coverage and efficacy are high among pre-adolescent girls, including boys in the vaccination program generally exceeds conventional thresholds of good value for money, even under favorable conditions of vaccine protection and health benefits.
Candidate for the Lee B. Lusted Student Prize Competition
