Cost and benefit of secondary prophylaxis for Pneumocystis carinii pneumonia

Abstract

Objective: To determine the relative cost and benefit of aerosolized pentamidine and the combination product of sulfamethoxazole and trimethoprim sulfate as secondary prophylaxis for Pneumocystis carinii pneumonia.

Design: A Markov-based cost-benefit analysis was performed. Drug efficacies, toxicities, and mortality rates were drawn from the current literature.

Setting: Hypothetical.

Patient population: Patients infected with the human immunodeficiency virus who had had at least one episode of P carinii pneumonia.

Interventions: Regimen 1 required the use of aerosolized pentamidine as the sole first-line prophylactic agent in all patients. Regimen 2 required the use of sulfamethoxazole-trimethoprim in all patients who had no history of a toxic reaction to the drug; only patients with a history of toxic effects and those who developed toxic effects while receiving the drug would receive aerosolized pentamidine. Regimen 3 required that no secondary prophylaxis be given.

Main outcome measures: Net cost, median patient survival, and 5-year survival for each regimen and for regimens 1 and 2 compared with regimen 3.

Main results: Regimen 2 was dominant, with a net cost of $6332 per patient and a median survival of 2.050 years. Compared with no prophylaxis, regimen 2 resulted in a savings of $16,503 per patient and a 0.696-year increase in median survival. Compared with regimen 1, regimen 2 resulted in a savings of $2904 and a 0.067-year increase in median survival.

Conclusions: Secondary prophylaxis for P carinii saves money and extends survival. Current data suggest that sulfamethoxazole-trimethoprim should be given whenever it can be tolerated. Use of aerosolized pentamidine as a first-line agent would result in a modest increase in cost and a decrease in life expectancy.