Costs and outcomes of alternative approaches to treating cytomegatovirus (CMV) retinitis in persons with AIDS (PWA)

Clinical trials have shown differences in mortality and morbidity among therapies for CMV retinitis in PWAs. We constructed a decision-analytic simulation model to compare survival, quality of life and cost associated with treatment with IV Foscarnet (IVF), IV Ganciclovir (IVG), and Oral Ganciclovir (ORG) In the model, 10,000 patients with CMV retinitis at baseline are assigned to each treatment and are followed at two-week intervals for one year. We obtained probability estimates for clinical events from published literature, clinical trial databases, and a panel of clinical experts. Cost estimates were derived from Medicaid and Medicare fee schedules. Expected outcomes, costs, and associated cost-effectiveness ratios are as follows: weeks of survival - IVF 40.9, IVG 34.6, and ORG 34.8; weeks of vision-adjusted survival - IVF 32.8, IVG 27.9, and ORG 28.1; direct medical cost - IVF $44,208; IVG $35,757; and ORG $32,861, incremental cost per incremental year of survival - IVF vs IVG $69,976, and IVF vs ORG $96,412, incremental cost per incremental year of vision-adjusted survival - IVF vs IVG $88,243; IVF vs ORG $122,416. In one-way sensitivity analysis, incremental cost per incremental year of vision-adjusted survival for IVF vs. IVG was moderately sensitive (>10% increase or decrease) to changes in cost of IVF during induction and maintenance, cost of IVG during maintenance, and mortality for IVF and IVG. We conclude that IVF results in longer survival than IVG, but is only moderately cost-effective ORG results in comparable survival, but is less costly than IVG.