To determine the impact of prophylactic therapy for respiratory syncytial virus (RSV) infections on subsequent hospitalizations and related lengths of stay and costs and to estimate whether prophylactic treatment was cost-effective.
Retrospective cohort study of the 1999-2000 RSV season. Propensity scores were used to identify an untreated comparison group to adjust for treatment selection bias.
State of Kansas Medicaid program.
The study population included children 10 months or younger at the start of the RSV season or born during the season who either were premature or had chronic lung disease. All children were continuously enrolled in Medicaid throughout the season.
Main Outcome Measures
Inpatient admission for RSV infections and associated lengths of stay and costs; cost-benefit analysis of drug costs per reduction in hospitalization costs.
The RSV-preventive treatments reduced the odds of hospitalizations to 0.47, lengths of stay by 74%, and hospitalization costs by $703. Given an average drug cost of $4687, the cost-benefit ratio was 6.67.
Despite the demonstrated efficacy of intravenous RSV immune globulin and palivizumab in clinical trials, use of these agents in actual practice has not generated expected outcomes in the Kansas Medicaid program. Although their use generated reductions in all 3 hospital-related outcomes, their costs overwhelmed these benefits.