Zidovudine for Chemoprophylaxis after Occupational Exposure to HIV-Infected Blood: An Economic Evaluation

Three approaches to the management of health care workers (HCWs) following percutaneous exposure to blood of previously unknown serological status were compared using cost-effectiveness analysis. In strategy A, all HCWs are offered zidovudine as soon as possible after exposure. The decision is made within 72 hours to (1) continue therapy with the drug for 4 weeks if the patient's blood is positive for human immunodeficiency virus (HIV) on testing or (2) discontinue therapy and follow-up if the patient's blood is HIV-negative. Strategy B is similar to A except that zidovudine is not offered. In strategy C the patient's blood is not tested and zidovudine is not offered. The results indicate that for every 100 HCWs managed with strategies A, B, and C, the total costs in Canadian dollars (Can $1.00 = U.S. $0.85) are $47,910, $38,849, and $110,834, respectively. The incremental cost per case of AIDS prevented by A relative to B is $300,140, and that prevented by A relative to C is -$6,244,000 (i.e., A results in savings relative to C).