Area Median Income and Metropolitan Versus Nonmetropolitan Location of Care for Acute Coronary Syndromes: A Complex Interaction of Social Determinants

Abstract

BackgroundMetropolitan versus nonmetropolitan status and area median income may independently affect care for and outcomes of acute coronary syndromes. We sought to determine whether location of care modifies the association among area income, receipt of cardiac catheterization, and mortality following an acute coronary syndrome in a universal health care system.Methods and ResultsWe studied a cohort of 14 012 acute coronary syndrome patients admitted to cardiology services between April 18, 2004, and December 31, 2011, in southern Alberta, Canada. We used multivariable logistic regression to determine the odds of cardiac catheterization within 1 day and 7 days of admission and the odds of 30‐day and 1‐year mortality according to area median household income quintile for patients presenting at metropolitan and nonmetropolitan hospitals. In models adjusting for area income, patients who presented at nonmetropolitan facilities had lower adjusted odds of receiving cardiac catheterization within 1 day of admission (odds ratio 0.22, 95% CI 0.11–0.46, P<0.001). Among nonmetropolitan patients, when examined by socioeconomic status, each incremental decrease in income quintile was associated with 10% lower adjusted odds of receiving cardiac catheterization within 7 days (P<0.001) and 24% higher adjusted odds of 30‐day mortality (P=0.008) but no significant difference for 1‐year mortality (P=0.12). There were no differences in adjusted mortality among metropolitan patients.ConclusionWithin a universal health care system, the association among area income and receipt of cardiac catheterization and 30‐day mortality differed depending on the location of initial medical care for acute coronary syndromes. Care protocols are required to improve access to care and outcomes in patients from low‐income nonmetropolitan communities.

Socioeconomic Status, Mortality, and Access to Cardiac Services After Acute Myocardial Infarction in Canada: A Systematic Review and Meta-analysis

“…Of the 19 included studies, 8 reported short-term (within 30 days of AMI) mortality, 11 , 16 , 22 , 23 , 24 , 25 , 26 , 27 10 reported on intermediate (31 days to 1 year) mortality, 11 , 21 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 and 4 reported on long-term mortality (> 1 year) post AMI. 11 , 32 , 33 , 34 Twelve studies reported on catheterization post-AMI, 11 , 16 , 21 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 35 , 36 and 9 on revascularization. 11 , 16 , 25 , 26 , 29 , 30 , 32 , 36 , 37 Four studies examined referral to or participation in cardiac rehabilitation.…”

“…Eleven studies included Ontario populations, 11 , 21 , 24 , 30 , 31 , 32 , 33 , 35 , 37 , 38 , 39 4 were from Alberta, 25 , 27 , 28 , 34 2 were from Quebec 26 , 36 and 2 included patients from more than 4 provinces 16 , 29 ( Table 1 ). Several patient cohorts overlapped across studies.…”

“… 11 , 21 , 31 , 32 , 33 Two study cohorts were obtained through Alberta administrative data with overlapping dates, 25 , 34 and another 2 study cohorts were identical, from the A lberta P rovincial Pr oject for O utcome A ssessment in C oronary H eart Disease (APPROACH) database. 27 , 28 All studies were cohort studies (n = 19), although one was a subanalysis of a larger randomized control trial. 39 The sample size at analysis ranged from 541 to 145,882.…”

“…First, we note that the included studies are relatively old; only two studies (representing one study cohort) included data beyond 2010, with their data being from 2004-2011. 27,28 With increasing expertise and availability of cardiac catheterization, it is unclear whether data from the late 1990s to early 2000s fully represent recent practice patterns. However, Alter et al noted that though overall coronary angiography rates increased from 1992 to 2001, higher-income groups experienced a disproportionately higher increase compared to lower income groups.…”

“…Four studies used the Ontario Myocardial Infarction Database (OMID), 24,30,35,37 five studies used data from the Socio-Economic and Acute Myocardial Infarction (SESAMI) study, 11,21,[31][32][33] two study cohorts were obtained through Alberta administrative data with overlapping dates, 25,34 and another two study cohorts were identical, from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) database. 27,28 All studies were cohort J o u r n a l P r e -p r o o f studies (n= 19), though one was a sub-analysis of a larger randomized control trial 39 . The sample size at analysis ranged from 541 to 145 882.…”