Respiratory Syncytial Virus–Associated Disease in Children Receiving Intensive Care

Importance Data defining respiratory syncytial virus (RSV)–associated critical illness, risk factors, and outcomes among older children and adolescents are limited. As RSV prevention options expand, improved characterization of RSV-associated disease burden across childhood is needed. Objectives To quantify RSV-associated intensive care unit (ICU) admissions and mortality among children aged 2 to 17 years and evaluate associations between pediatric complex chronic conditions (CCCs) and mortality. Design, Setting, and Participants This retrospective, multicenter cohort study was performed from January 1, 2017, to June 1, 2023, among children aged 2 to 17 years admitted to ICUs. Data were analyzed from January to March 2026. Exposure RSV identified by laboratory testing or diagnosis codes. Main Outcomes and Measures Primary outcome was hospital mortality. Bivariate associations between mortality and covariates were calculated, and multivariable logistic regression was used to identify variables associated with mortality. Results This study included 6430 RSV-associated ICU admissions for children aged 2 to 17 years (8.3% of 77 395 ICU admissions; median [IQR] age, 6.6 [3.4-12.6] years; 3457 [53.8%] male). The median (IQR) ICU length of stay was 2.9 (1.5-6.8) days, and the median (IQR) hospital LOS was 5.9 (3.0-14.3) days. Positive pressure ventilation was used in 2061 admissions (32.0%), vasoactive agents in 1788 (27.8%), and both in 903 (14.0%). Hospital mortality occurred in 484 admissions (7.5%) and accounted for 484 of 735 RSV-associated deaths (65.9%) across all ages. At least 1 CCC category was present in 3680 admissions (57.2%) and 454 of 484 deaths (93.8%); 3 or more CCC categories were present in 1666 admissions (25.9%) and 332 of 484 deaths (68.6%). Higher CCC burden was associated with mortality, particularly with 3 or more CCCs (mortality odds ratio [MOR 22.56; 95% CI, 15.44-32.97). CCC burden was associated with older age but remained associated with mortality across age strata. In adjusted analyses, malignant neoplasm (adjusted MOR ([aAMOR), 4.27 [95% CI, 3.16-5.77]), neurologic or neuromuscular (aAMOR, 2.66 [95% CI, 2.08-3.39]), respiratory (aAMOR, 2.36 [95% CI, 1.83-3.03]), transplant (aAMOR, 2.18 [95% CI, 1.47-3.23]), congenital or genetic, metabolic, and cardiovascular disease as well as technology dependence remained associated with mortality. Conclusions and Relevance In this cohort study of 6430 RSV-associated ICU admissions among children aged 2 to 17 years, older children and adolescents represented a substantial proportion of severe RSV-associated disease and mortality; deaths were concentrated among children with CCCs. These results suggest that high-risk pediatric subpopulations may benefit from RSV prevention.