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.