The estimated direct medical cost of sexually transmitted diseases among American youth, 2000

Perspectives on Sexual and Reproductive Health, Jan-Feb, 2004 by Harrell W. Chesson, John M. Blandford, Thomas L. Gift, Guoyu Tao, Kathleen L. Irwin

We drew cost estimates for physician visits, follow-up Pap and HPV tests, colposcopy and treatment of cervical neoplasia from a previous study, (13) subtracting indirect costs for patient time. (14) We assumed that cervical intraepithelial neoplasia occurs, on average, three years after initial HPV infection, and discounted treatment costs accordingly. (15) The decision analysis model estimated the discounted HPV-attributable cost per abnormal Pap test at $1,281. With the estimated 2.8 million abnormal Pap test results per year, direct HPV-attributable costs of recommended follow-up to abnormal cervical cytology and treatment of related neoplasia totaled $3.6 billion among women of all ages.

We projected 12,800 cases of invasive cervical cancer annually, distributed as 57.5% localized to the cervix, 34.0% with pelvic involvement and 8.5% with more distant spread. (16) When the costs of patient rime were excluded, estimated invasive cervical cancer costs were $20,255 for localized disease, $21,678 for pelvic disease and $36,912 for distant disease. (17) We discounted the cost estimates based on the assumption that diagnosis of invasive cancer occurs, depending on stage, 21-25 years after initial HPV infection. (18) On the basis of these figures, the total discounted annual cost of invasive cervical cancer among all age-groups in the United States (i.e., including women aged 25 or older) was estimated at $146.4 million.

* HPV and anogenital warts. The average cost of treatment after a new diagnosis of external anogenital warts was $446 (details available from the author). Approximately 20-30% of episodes of anogenital warts resolve without treatment. (19) Because not all persons with such warts seek or require therapy to remove them, we adjusted our estimates according to the assumption that 25% of cases resolve without treatment. Estimates of annual incidence of anogenital warts vary widely, from 250,000-500,000 to 500,000-1,000,000. (20) To estimate the economic burden of HPV, we assumed an incidence of 500,000. Given these assumptions, the annual total direct cost associated with anogenital watts for all age-groups is $167.4 million.

* Economic burden of infection acquired during youth. To estimate the burden of HPV infection in adolescents and young adults, we adjusted total cost figures to reflect the proportion of persons infected between ages 15 and 24. The attributable total costs of HPV infection among women were adjusted to reflect the results of a model of the natural history of HPV infection and progression, which found that 74% of incident cervical HPV infections occur among women in this age-group. (21) We assumed that the cumulative incidence of HPV infection was comparable among young men (22) and assigned the economic burden of treatment for anogenital warts accordingly.

This adjustment implies that costs attributable to HPV infection in youth include $2.7 billion for the follow-up of abnormal Pap results and treatment of cervical neoplasia, $108.3 million for direct medical costs associated with invasive cervical cancer and $123.9 million for the treatment of external anogenital warts. The total annual cost of HPV infection attributable to infections acquired through age 24 is $2.8 billion for women and $62 million for men. This total cost estimate is more than twice that of an earlier study; (23) much of the difference results from the incorporation of costs linked to diagnosis and management of cytologic abnormalities. Assuming 4.6 million infections among those aged 15-24, distributed equally between the sexes, (24) the expected cost per HPV infection is $1,228 for women and $27 for men.