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

With some exceptions, our cost-per-case estimates are not age-specific. Rather, we based them on existing studies that typically reflect STD costs among adults rather than adolescents. For example, we assumed that the distribution of high- and low-risk HPV types is independent o f the age at infection. If the distribution of HPV types vanes by age, we may have overestimated or underestimated the true cost of HPV infection in adolescents and young adults. In addition, the estimated costs of HIV and HSV include long-term drug therapy. If young people require more years of such treatment than was estimated for the adult populations on which our sources are based, the actual cost of HIV and HSV among youth could exceed our estimates.

In calculating the costs by STD, we may have double-counted certain costs in instances in which a person was infected with more than one STD at a given rime. For example, a person infected with both gonorrhea and chlamydia might have both infections diagnosed at the same doctor visit. However, some patients presenting with gonorrhea alone (or chlamydia alone) may be presumptively treated for the other infection as well because coinfection is common. Thus, any overestimation of the cost of diagnostic visits for a person infected with both chlamydia and gonorrhea would be offset, at least in part, by the added costs of presumptive dual treatment for persons who are not infected with both organisms. Data are not available to determine the net effect of these two possibilities on our cost estimates for gonorrhea and chlamydia; it likely is far less than the impact of our use of conservative estimates of the rates of progression to PID and cost of PID attributable to gonorrhea and chlamydia.

We did not consider every possible direct medical cost of each STD. For example, we limited estimates of the economic burden of HPV among youth to management of cervical manifestations among women and anogenital warts among both sexes. To the extent that HPV is an important factor in other male and female genital cancers and internal genital warts, we underestimated the economic burden of HPV infection. STD infections in pregnant women can cause pregnancy complications and medical problems for infants who are infected during the perinatal period. Because we did not include these costs, we likely underestimated the cost of STDs among young women.

We did not include the cost of primary STD and HIV prevention activities (for example, finding and notifying partners of infected persons) or the cost of protecting the nation's blood supply from these diseases. Similarly, we did not include the cost of large-scale screening for STDs that often lack symptoms or have symptoms or signs that are not easily recognized. For example, the costs of routine prenatal syphilis and HIV screening programs and routine chlamydia screening programs for sexually active adolescent and young adult women were not included. However, costs associated with screening tests that yield a positive result, as well as subsequent diagnostic tests required because of the positive screening result, were included because these costs must be incurred to detect and treat infection. Although these screening costs would have been incurred regardless of test outcome, the inclusion of these costs for positive tests has little effect on the estimated burden of STDs.