Respiratory Syncytial Virus-Associated Hospitalization Rates among US Infants: A Systematic Review and Meta-Analysis

Background Although global reviews of infant respiratory syncytial virus (RSV) burden exist, none have summarized data from the United States or evaluated how RSV burden estimates are influenced by variations in study design. Methods We performed a systematic literature review and meta-analysis of studies describing RSV-associated hospitalization rates among US infants and examined the impact of key study characteristics on these estimates. Results We reviewed 3328 articles through 14 August 2020 and identified 25 studies with 31 unique estimates of RSV-associated hospitalization rates. Among US infants <1 year of age, annual rates ranged from 8.4 to 40.8 per 1000 with a pooled rate of 19.4 (95% confidence interval [CI], 17.9-20.9). Study type influenced RSV-associated hospitalization rates (P = .003), with active surveillance studies having pooled rates (11.0; 95% CI, 9.8-12.2) that were half that of studies based on administrative claims (21.4; 19.5-23.3) or modeling approaches (23.2; 20.2-26.2). Conclusions Applying our pooled rates to the 2020 US birth cohort suggests that 79 850 (95% CI, 73 680-86 020) RSV-associated infant hospitalizations occur each year. The full range of RSV-associated hospitalization rates identified in our review can better inform future evaluations of RSV prevention strategies. More research is needed to better understand differences in estimated RSV burden across study design. Based on study results, an estimated 80 000 respiratory syncytial virus (RSV)-associated infant hospitalizations occur each year in the United States. More research is needed to better understand differences in estimated RSV burden across study design.