Esophageal candidiasis in patients infected with the human immunodeficiency virus. A decision analysis to assess cost-effectiveness of alternative management strategies.

BACKGROUND

Currently no consensus exists concerning the timing of upper endoscopy and the choice of antifungal therapy for patients infected with the human immunodeficiency virus who also have esophageal candidiasis. The objective of this research was to determine the clinical and economic effects of alternative management strategies for these patients.

METHODS

Decision analysis was used to evaluate the outcomes, costs, and cost-effectiveness of two strategies for the diagnostic workup and treatment of patients infected with the human immunodeficiency virus with dysphagia and/or odynophagia: (1) empiric--a strategy to treat all patients empirically with an oral antifungal agent for up to 4 weeks; and (2) initial esophagogastroduodenoscopy (EGD)--a strategy to perform EGD on all patients and to treat only those with esophageal candidiasis with an oral antifungal agent for up to 4 weeks. Within each strategy, three antifungal regimens were evaluated: ketoconazole, 200 mg daily; fluconazole, 100 mg daily; and ketoconazole, 200 mg daily, for 2 weeks followed by fluconazole, 200 mg daily, for 2 weeks in nonresponders. Information on the probability of esophageal candidiasis in patients with esophageal symptoms and the efficacy of antifungal therapy was obtained from the literature. The costs for diagnostic workup were estimated using both teaching hospital charges and Medicare reimbursement payments. The costs of antifungal therapy were estimated from local pharmacy charges. The average cost per complete response and incremental cost-effectiveness were calculated and subjected to sensitivity analysis.

RESULTS

Using the best available evidence for antifungal efficacy, empiric fluconazole was the most cost-effective strategy for all probabilities of esophageal candidiasis that were more than 0.55. Using teaching hospital charges in our base-case analysis, the average costs per complete response for empiric fluconazole and initial EGD and fluconazole were $2706 and $3141, respectively. The incremental cost-effectiveness of initial EGD and fluconazole compared with empiric fluconazole was $3792 per additional complete response. When the cost-effectiveness of the two strategies was compared as the cost of diagnostic workup was varied, initial EGD and fluconazole became the dominant strategy when the diagnostic workup cost fell below $710, a figure that is less than the current Medicare reimbursement payment.

CONCLUSIONS

From the perspective of the payer of medical care, empiric fluconazole is the most cost-effective strategy for the initial management of patients infected with the human immunodeficiency virus with esophageal symptoms.