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

To calculate the total direct medical cost for each STD, we multiplied the estimated cost per case by the estimated number of new cases that occurred in 2000 among persons aged 15-24 (Table 1). (8)

HIV

Estimates of the discounted lifetime medical cost per new case of HIV were obtained from an existing study. (9) We applied the midpoint ($199,800) of the two estimates ($176,500 and $223,300) from that study's intermediate cost scenario, which included the following assumptions: Persons with HIV live for 16 years after becoming infected; each infected person is unaware of his or her infection in the first two years and begins viral load monitoring (but not treatment) in the third year; and in years 4-16 after infection, the person receives antiretroviral therapy, prophylaxis and treatment for opportunistic infections, as well as other medical care associated with progression to AIDS. This estimated lifetime cost ($199,800) is consistent with the findings of a study that indicated that the average annual cost of care was approximately $20,900 for adults receiving care for HIV in 1998. (10) For example, when a 3% annual discount rate is applied, the cost of 12 years of care at $20,900 per year would be about $214,000 if care began immediately after infection, and would be about $174,000 if care began seven years after infection. This example is conservative, however, in assuming that only 12 years of care would be required; estimated life expectancy following HIV infection is 22-26 years for persons receiving antiretroviral treatment. (11) Thus, the estimated cost per case of HIV that we apply may be a lower-bound estimate of the true cost.

HPV

Out estimate of the total medical cost attributable to an HPV infection in youth focused on costs associated with cervical abnormalities in women and external anogenital warts in both men and women. * We first calculated the average cost of a new HPV infection in the general population, then made an adjustment based on the likelihood that the infection occurred by the age of 24.

* Cervical abnormalities. For adolescent and young adult women, we based the analysis on reported costs associated with diagnosis and management of cytologic abnormalities, preinvasive cervical neoplasia and invasive cervical cancer, and then retrospectively estimated the portion of the costs of these conditions attributable to HPV. ([dagger])

Because published estimates of the cost per case were not available, we constructed a decision analysis model to calculate the expected cost of an abnormal cervical cytology finding in women. Potential management strategies following an abnormal Pap test result were based on the 2001 Bethesda guidelines, a set of evidence-based recommendations developed in a consensus conference sponsored by the American Society for Colposcopy and Cervical Pathology. (12) For all atypical Pap test findings, we attributed fully to HPV the costs associated with the diagnosis and treatment of histologically confirmed findings of cervical intraepithelial neoplasia grades 1-3 and of invasive cervical cancer (details available from the author).