Socio-Economic Inequities in the Age-Specific Burden of Severe Respiratory Syncytial Virus (RSV) in Canada, 2016-2019

Background Socio-economic status (SES) is an important determinant of severe respiratory infections. Despite being a leading cause of hospitalization, limited attention has been given to social inequities in respiratory syncytial virus (RSV), particularly outside of childhood and beyond neighbourhood-level measures. This study aimed to quantify the burden of severe RSV disease across the age continuum by individual-level SES indicators. Methods We conducted a longitudinal descriptive study of Canadians (excluding Québec) ≥6 months of age using linked socio-demographic and hospitalization data from the 2016 Canadian Census Health and Environment Cohort (2016-2019). Crude and age-stratified International Classification of Diseases, 10th Revision, Canada (ICD-10-CA) coded RSV-related hospitalization rates, rate ratios (RRs), and rate differences (RDs) per 100,000 person-years were estimated across SES indicators using Poisson regression. Results Rates of RSV-related hospitalization were greatest among Canadians with lower compared to higher SES, as indicated through multiple measures including income (RD: 11.7 [95% confidence interval, 10.1-13.3]; RR: 2.8 [2.4-3.2]), education (RD: 18.7 [16.6-20.9]; RR: 3.3 [2.9-3.7]), and various indicators of poorer housing conditions including unaffordable housing and apartment-living. Inequities in RSV-related hospitalization varied by SES measure and age group; while rates were highest among 6-59-month- and ≥80-year-olds overall, some of the greatest relative SES inequities were among other age groups. Conclusions This work highlights novel individual-level social determinants influencing the burden of severe RSV disease. In addition to clinical characteristics, understanding SES factors role in age-specific RSV-related hospitalization risk is necessary to inform equitable prevention efforts, including delivery of emerging RSV immunizations.