Income-related inequalities in ACSC hospitalization in Canada: evidence from 2005-2019 surveys linked with...

This study examines income-related inequalities in hospitalizations due to ambulatory care-sensitive conditions (ACSCs) in Canada, using linked data from the Canadian Community Health Surveys (2005-2019), the Discharge Abstract Database, and the T1 Family File across nine provinces. We quantify inequalities in ACSC hospitalizations using the Erreygers concentration index (ECI) and ACSC hospitalization costs using the standard concentration index (CI). The recentered influence function-ordinary least squares estimator (RIF-CI/ECI-OLS) was used to decompose income inequalities in ACSC hospitalizations. Additionally, the RIF-based Blinder-Oaxaca (BO) method decomposes disparities by sex, age, income, and rurality. ECI/CI findings reveal that ACSC hospitalizations are disproportionately concentrated among lower-income individuals (ECI: -0.0040 to -0.0060; CI: -0.2519 to -0.3957). Individuals above the low-income cut-off group (ECI: -0.0040 to -0.0051; CI: -0.2582, to -0.3465), older adults (ECI: -0.0033 to -0.0178; CI: -0.0806 to -0.3631) and those living in rural areas (ECI: -0.0057 to -0.0112; CI: -0.2779 to -0.3829) experience relatively greater inequalities. Individuals aged 66-74 years, those with less than secondary education, those with multimorbidity, and widowed, separated, and divorced individuals are associated with increased inequality, whereas those from the low-income cut-off group and immigrants are associated with reduced inequality. The RIF-based BO decomposition analysis reveals significant income-related inequalities in ACSC hospitalization and ACSC hospitalization costs by age and rurality. Our findings suggest that targeted policies may be necessary to enhance access to primary care for older adults, individuals with multimorbidity, low-income individuals, and those living in rural areas.