Educational inequalities in 28 day and 1-year mortality after hospitalisation for incident acute myocardial infarction--a nationwide cohort study

Background: There is little recent evidence on the impact of comorbidities and access to revascularisation procedures on educational inequalities in mortality after acute myocardial infarction (AMI). The aim of the study was to investigate educational inequalities in mortality among all patients hospitalised for an incident AMI during 2001-2009 in Norway.

Methods: Data were obtained through the Cardiovascular Disease in Norway (CVDNOR) project. Incident AMI was defined as an AMI-hospitalisation without any AMI-events in the previous 7 years. Education was categorised as basic, upper secondary or tertiary (college/university). Cox regression was used to assess educational differences in 28-day and 29-365-day mortality after an incident AMI in terms of hazard ratios and relative index of inequality (RII). RII can be interpreted as the ratio in mortality between the 0 th and the 100th percentile of the education distribution.

Results: 111 993 incident AMIs were included (39.4% women). Among patients aged 35-69, RIIs (95% CI) adjusted for age, sex and year were 1.86 (1.59-2.18) and 2.10 (1.69-2.59) for 28-day and 29-365-day mortality respectively. Among patients aged 70-94 the corresponding RIIs were 1.12 (1.06-1.30) and 1.28 (1.19-1.38). Educational inequalities in mortality were attenuated after adjustment for comorbidities and revascularisation, but were still significant. Educational inequalities did not decrease during 2001-2009.

Conclusion: Educational inequalities in both 28-day and 29-365 day mortality were strong and persistent during 2001-2009. Further research is needed to investigate if these disparities are driven by inequalities in the severity of the AMI or by inequitable access to treatment and rehabilitation.