A new cost-utility analysis assessing risk factor-guided prophylaxis with palivizumab for the prevention of severe respiratory syncytial virus infection in Italian infants born at 29–35 weeks’ gestational age

Since the last Italian cost-utility assessment of palivizumab in 2009, new data on the burden of respiratory syncytial virus (RSV) and an International Risk Scoring Tool (IRST) have become available. The objective of this study was to provide an up-to-date cost-utility assessment of palivizumab versus no prophylaxis for the prevention of severe RSV infection in otherwise healthy Italian infants born at 29-31 weeks' gestational age (wGA) infants and those 32-35wGA infants categorized as either moderate- or high-risk of RSV-hospitalization (RSVH) by the IRST. A decision tree was constructed in which infants received palivizumab or no prophylaxis and then could experience: i) RSVH; ii) emergency room medically-attended RSV-infection (MARI); or, iii) remain uninfected/non-medically attended. RSVH cases that required intensive care unit admission could die (0.43%). Respiratory morbidity was considered in all surviving infants up to 18 years of age. Hospitalization rates were derived from Italian data combined with efficacy from the IMpact-RSV trial. Palivizumab costs were calculated from vial prices (50mg: euro490.37 100mg: euro814.34) and Italian birth statistics combined with a growth algorithm. A lifetime horizon and healthcare and societal costs were included. The incremental cost-utility ratio (ICUR) was euro14814 per quality-adjusted life year (QALY) gained in the whole population (mean: euro15430; probability of ICUR being