Table 1 Study inclusion and exclusion criteria
Component | Explanation |
|---|---|
Population | Inclusion: Study population has a mean age ± 1 SD < 75 years of age. If this criteria could not be evaluated due to missing data, the study was still included. Exclusion: • Pediatric studies were excluded during full-text review as both the concept and effect of SES on health outcomes differs in childhood relative to adulthood, and thus these studies were determined to be out of scope. |
Exposure | Inclusion: Individual- or area-level SES defined as income, education, occupation, and social class in accordance with the WHO Commission on Social Determinants of Health conceptual framework. Exclusion: • SES was not the clear primary exposure of interest, including studies that did not include SES in their title or objectives, evaluated multiple predictors of interest (e.g. person and health system characteristics), or adjusted for SES as a confounding variable as these studies were not optimally designed to evaluate the effects of SES, decreasing interpretability of effect sizes. Exception: Studies that only included demographic and health status covariates as these are potential SES confounding variables, and SES effect sizes could be reasonably interpreted. • Only proxy measures for SES were used (e.g. car ownership, insurance status). |
Outcome | Inclusion: Hospitalization, including emergency department visits, for chronic ACSCs. Both aggregate and condition-specific outcomes were included. Studies were included if aggregate outcomes included other ACSCs in addition to chronic ACSCs listed in this review. Exclusion: • Sole study outcome was length of stay or hospital readmissions as readmitted individuals were considered at greater risk of hospitalization relative to the general population. • Selected chronic ACSCs were narrowed during full-text review, excluding iron-deficiency anemia and atrial fibrillation and flutter, to be consistent with the Canadian definition (ie. angina, asthma, CHF, COPD, diabetes and diabetic complications, epilepsy and seizures, and hypertension). • Outcome was risk of hospitalization for an ACSC relative to a non-ACSC. |
Study Setting | Inclusion: Countries with high-income economies. |
Study Design | Inclusion: Observational (i.e. cross-sectional, case-control, or cohort). Exclusion: • Purely descriptive studies that did not clearly articulate the SES-ACSC relationship using measures of effect (i.e. risk ratio, rate ratio, odds ratio, hazard ratio, Relative Index of Inequality, Slope Index of Inequality). |
Publication | Inclusion: • Written in the English language. • Published between January 1, 1990 to July 31, 2018. • Published in a peer-reviewed journal. |