A utility assessment of oral and intravenous ganciclovir for the maintenance treatment of AIDS-related cytomegalovirus retinitis

Abstract

The purpose of this study was to determine the magnitude of the difference in patient preference/utility for intravenous (i.v.) ganciclovir compared with oral ganciclovir for maintenance treatment of cytomegalovirus (CMV) retinitis. We used a cross-sectional, interviewer-administered time trade-off (TTO) exercise with hypothetical health state descriptions, based upon data from clinical trials and the published literature. The study was conducted in a private clinic in Sydney Australia, specialising in the care of people with HIV. A total of 80 individuals with HIV infection who had not developed AIDS were administered the TTO instrument. The main outcome measure was the difference between each respondent's utility score for oral and i.v. ganciclovir maintenance therapy. When the 80 HIV-positive patients were presented with information on drug efficacy, adverse effects and mode of administration, 60 (75%) preferred oral ganciclovir, 4 patients preferred i.v. ganciclovir, and 16 were indifferent. The median utilities were 0.837 (oral ganciclovir) and 0.475 (i.v. ganciclovir). The difference in rankings was statistically significant by Wilcoxon's signed-ranks test (Z = -6.69, p < 0.00005). The median utility scores suggest that, all other things being equal, individuals with HIV infection would prefer an oral formulation of ganciclovir to i.v. administration in the event of CMV retinitis infection.