Short report: Agreement between individual- and area-level measures of socioeconomic status (SES) in Canada

While area-level socioeconomic status (SES) is an important construct, it is also often used as a proxy for individual SES in the absence of person-level data. The ability for these measures to capture the same populations across the life course is unclear.

We estimated concordance between individual- and area-level after-tax household income, a common measure of SES, among the 2016 Canadian Census Health and Environment Cohort. We used weighted Kappa statistics (where, for example, values 0-0.2 are interpreted as none-slight agreement and 0.81-1.0 as almost perfect agreement), including 95% confidence intervals (95%CIs), calculated overall and by age (<5, 5-17, 18-64, ≥65 years). Sociodemographic profiles of included populations were compared across income measures.

Agreement between individual- and area-level income was considered fair overall (weighted Kappa: 0.2480 [95%CI: 0.2476-0.2485]); trends were consistent across age groups with estimates ranging from 0.2157 (95%CI: 0.2145-0.2168) to 0.2838 (95%CI: 0.2819-0.2858) among those ≥ 65 and < 5 years old, respectively. Differences in the sociodemographic profiles (e.g., employment, housing) of populations within each quintile were apparent between measures.

Individual- and area-level SES measures may capture populations differently. Understanding the comparability of these measures is important for informing public health planning aimed at reducing health inequities.