An intersectional analysis of sex and income inequities in cardiac rehabilitation enrollment

Abstract Background Cardiac rehabilitation remains underutilized, and disparities persist. Women are underrepresented, and costs are often cited as a barrier to participation. Despite international calls to develop health surveillance systems to monitor outcomes and address the needs of women, there is a paucity of research exploring barriers to cardiac rehabilitation enrollment through an intersectional lens. Purpose To explore how financial barriers intersect with sex/gender to shape access to cardiac rehabilitation in the province of Manitoba, Canada. We use the term sex/gender to denote that both biology and socioeconomic status affect enrollment. Methods We conducted a descriptive, cross-sectional study using data from electronic medical records at two cardiac rehabilitation centres. Data from referrals between 2016 and 2019 were linked to Statistics Canada census income data for 31 urban areas, identified by the first three characters of the postal code. Census income data quality was first examined for missingness to ensure transparency and guide sensitivity analyses. We selected the Low-Income Measures-After Tax (LIM-AT), an area-level metric that indicates the proportion of households earning less than half the median income. The measure considers household size and provides a more accurate reflection of those with lower disposable income who may be unable to afford cardiac rehabilitation, as compared to income alone. Each area was divided into quintiles based on the prevalence of LIM-AT. Enrollment rates of the highest and lowest income quintiles were then compared by sex, as recorded in the electronic medical record, using Chi-square tests. Age differences between males and females were examined using an unpaired t-test. A p 0.05 was considered significant, and Bonferroni adjustments were applied post-hoc for multiple comparisons. Results Analyses included 5569 referrals (3863 males and 1706 females). Six of the 31 urban areas had missing income data ranging from 10% to 20%. Females were older than males (95% CI 2.3 to 3.7 years, p 0.0001). Those in the lowest-income quintile enrolled less often than those in the highest quintile, at 39.1% vs. 56.3%, χ² (1, N = 1967) = 58.5, p 0.0001. Females had lower enrollment rates than males, χ² (1, N = 5569) = 36.3, p 0.0001. There were associations between sex-income quintile and enrollment χ² (3, N = 1967) = 75.3, p 0.00001. Pairwise tests with the Bonferroni adjustment revealed that the greatest disparity was observed between the lowest-income females and the highest-income males, χ² (1, N = 1056) = 53.5, adjusted p 0.0006. Sensitivity analyses, excluding areas with moderate (10-20%) missing income data, yielded similar patterns. Conclusions Interventions are necessary to enhance cardiac rehabilitation enrollment among low-income groups, particularly among low-income females.For image description, please refer to the figure legend and surrounding text.