Objective To evaluate the cost-effectiveness (CE) of palivizumab as respiratory syncytial virus (RSV) prophylaxis in premature infants 32 to 35 weeks gestational age (GA), without chronic lung disease.

Methods A decision analytic model was designed to compare direct and indirect medical costs of the patient with future lost productivity and benefits of prophylaxis. Five types of sensitivity analyses were performed to ascertain robustness of the model based on mortality, health utility scales, variable discounting rates, administration costs and vial sharing.

Setting Canadian publicly funded health care system (base-case analysis).

Primary Outcomes Expected costs and incremental CE ratio expressed as cost per quality-adjusted life-year (QALY) gained using $ Canadian (CAD) 2006.

Results Expected costs were higher for palivizumab prophylaxis compared with no prophylaxis. The incremental CE ratio for the base-case scenario was $17,253 per QALY after discounting, which is considered highly cost-effective. The model was not sensitive to variation in the RSV mortality rate. Sub-analyses varying the number of risk factors in a Canadian validated risk-scoring tool were sensitive to the resulting variation in RSV-related hospitalization rates. In instances where one risk factor or less was present, palivizumab was not cost-effective. However, for infants with two or more risk factors, or at least moderate risk, palivizumab had incremental costs per QALYs that indicated moderate to strong evidence for adoption (range: −$2,881 [cost savings] to $77,668 per QALY).

Conclusions Palivizumab was cost-effective and our model supports prophylaxis for infants born at 32 to 35 weeks GA, particularly those with two or more risk factors.