Association of Socioeconomic Factors and Severity of Bronchiolitis Hospitalizations

It is unclear if socioeconomic status (SES) factors influence severity of illness of patients hospitalized with bronchiolitis. This study was conducted to identify SES factors including the Center for Disease Control and Prevention's Social Vulnerability Composite Index (SVI), estimated income, proportion of minority, proportion of living below poverty, insurance status, and number of household members associated with length of stay (LOS) and intensive care unit admission. Infants hospitalized at a tertiary care urban center for bronchiolitis were identified using International Classification of Diseases codes. Federal information processing system codes were identified from home address and paired with SVI and 2018 census tract. Other measures of SES were obtained from the Federal Financial Institutions Examination Council. Number of household members, insurance, age, sex, and history of prematurity were recorded from patient chart. Length of stay was modeled with mixed effects negative binomial regression and pediatric intensive care unit (PICU) admission with mixed effects logistic regression with random intercept at the census tract and adjustment for clinical factors. A total of 417 infants had median age of 144 days (interquartile range (IQR): 61, 357) and 136 (33%) were born premature. Median LOS was 62 hours (24, 136) with 97 (23%) patients admitted to the PICU. Median household members were 4 (4, 5). For each increase in household member, there was 7% increase in LOS (incidence rate ratio 1.07, 95% confidence interval: 1-1.14, P = .038). Social Vulnerability Composite Index, subcategories, insurance status, estimated income, percent of minority, and percent of poverty did not show any associations with length of hospitalization or PICU admission. Increasing number of household members may be associated with increased bronchiolitis hospital LOS. We find no associations with other SES measures.