Abstract 14: Sex, Gender, Socioeconomic Status and Access to Cardiac Catheterization in the Context of Universal Healthcare Coverage
Authors: Fabreau Gabriel E , Leung Alexander A , Southern Danielle A , Ayanian John Z , Ghali William A 
Published: July 2021

Background:
Sex and gender disparities have been described in cardiac care and outcomes following acute coronary syndromes (ACS). Socioeconomic status (SES) may also affect medical care and health outcomes, partly through barriers in access to cardiac catheterization. In Canada, a universal healthcare system may reduce these barriers. We sought to determine whether sex/gender and SES interact to modify the receipt of cardiac catheterization and mortality following an ACS in a universal healthcare system.

Methods:
Using a provincial multicenter cardiac registry, we assembled a cohort of 14,012 patients admitted with an ACS to any cardiology service in the southern health zones of Alberta, Canada between April 18, 2004 and December 31, 2011 by linking census, vital statistics and clinical registry data. SES was estimated using residential neighbourhood median household income from the 2006 Canadian census. We compared the odds of receiving a cardiac catheterization within 1 and 30 days of admission, and the odds of death within 30 days and 1 year of admission by income quintiles and stratified by sex. Using multivariable logistic regression we controlled for age, geography, cardiac risk factors and clinical comorbidities to estimate the adjusted odds ratios (ORs) of receiving cardiac catheterization and of death.

Results:
Unadjusted rates of catheterization were higher for men compared to women, with 41% (4048 of 9995) vs. 31% (1237 of 4017) at one day, and 72% (7166 of 9995) vs. 62% (2495 of 4017) at 30 days (p<0.001 for both time points). Further, men had lower mortality rates with 2% (200 of 9995) vs. 2.8% (112 of 4017) at 30 days, and 5.2% (520 of 9995) vs. 7.4% (297 of 4017) at 1 year (p<0.001 for both time points). In models adjusting for SES, women were less likely to receive cardiac catheterization within 1 day (OR 0.79, 95% confidence interval [CI], 0.71 - 0.87) and 30 days (OR 0.73, 95% CI, 0.62-0.86) of admission with an ACS. When examined across SES quintiles, adjusted models revealed differing relationships for men vs. women: each incremental decrease in income quintile was associated with a 7% lower odds of receiving catheterization for women (p=0.005) vs. a smaller 3% decrement in odds for men (p=0.03). Additionally, among women, each decrease in income quintile was associated with a 13% higher odds of 30-day mortality (p=0.02) vs. a 4% higher odds of 30-day mortality for men (p=0.39).

Conclusion:
The relationships between SES and use of cardiac catheterization and mortality after ACS differ for men vs. women, with women seemingly more vulnerable to the detrimental associations of low income. These findings were present despite a universal healthcare system. This suggests that factors other than insurance status are at play, and that elements of sex and/or gender are effect modifiers. Care protocols designed to improve access to care and outcomes in women, especially low SES women, are required.