Context Recently published results suggest that effective vaccines against cervical
cancer—associated human papillomavirus (HPV) may become available within
the next decade.
Objective To examine the potential health and economic effects of an HPV vaccine
in a setting of existing screening.
Design, Setting, and Population A Markov model was used to estimate the lifetime (age 12-85 years) costs
and life expectancy of a hypothetical cohort of women screened for cervical
cancer in the United States. Three strategies were compared: (1) vaccination
only; (2) conventional cytological screening only; and (3) vaccination followed
by screening. Two of the strategies incorporated a vaccine targeted against
a defined proportion of high-risk (oncogenic) HPV types. Screening intervals
of 1, 2, 3, and 5 years and starting ages for screening of 18, 22, 24, 26,
and 30 years were chosen for 2 of the strategies (conventional cytological
screening only and vaccination followed by screening).
Main Outcome Measures Incremental cost per life-year gained.
Results Vaccination only or adding vaccination to screening conducted every
3 and 5 years was not cost-effective. However, at more frequent screening
intervals, strategies combining vaccination and screening were preferred.
Vaccination plus biennial screening delayed until age 24 years had the most
attractive cost-effectiveness ratio ($44 889) compared with screening
only beginning at age 18 years and conducted every 3 years. However, the strategy
of vaccination with annual screening beginning at age 18 years had the largest
overall reduction in cancer incidence and mortality at a cost of $236 250
per life-year gained compared with vaccination and annual screening beginning
at age 22 years. The cost-effectiveness of vaccination plus delayed screening
was highly sensitive to age of vaccination, duration of vaccine efficacy,
and cost of vaccination.
Conclusions Vaccination for HPV in combination with screening can be a cost-effective
health intervention, but it depends on maintaining effectiveness during the
ages of peak oncogenic HPV incidence. Identifying the optimal age for vaccination
should be a top research priority.