Neighborhood socioeconomic status and leisure-time physical activity after myocardial infarction: A longitudinal study.

BACKGROUND: Area-level SES is independently associated with myocardial infarction (MI) prognosis, yet the mechanisms for this association remain speculative.
PURPOSE: Using a population-based cohort of MI patients, this study examined whether neighborhood SES predicts long-term trajectory of leisure-time physical activity (LTPA), an established prognostic factor.
METHODS: Patients aged ≤65 years (n=1410) admitted to hospital in central Israel with first MI in 1992-1993, were followed up through 2005. LTPA was reported on five successive occasions: at baseline, 3-6 months, 1-2 years, 5 years, and 10-13 years post-MI. Generalized estimating equations (GEEs) with ordinal outcome variable (LTPA classified as regular, irregular, or none) were used to determine the independent predictive role of neighborhood SES in LTPA trajectory post-MI. Analyses were conducted in 2010-2011.
RESULTS: Engagement in LTPA was poor, with point prevalence rates ranging from 33% to 37% for inactivity and from 19% to 27% for irregular activity throughout follow-up. The GEE-derived ORs (95% CIs) for decreased LTPA level in the lower and middle vs upper neighborhood SES tertiles were 2.49 (2.05, 3.02) and 1.60 (1.33, 1.92) after age and gender adjustment, and 1.55 (1.26, 1.90) and 1.23 (1.02, 1.49) after multivariable adjustment for individual SES measures, cardiovascular risk factors, MI characteristics, and disease-severity indices, respectively (p for trend <0.001).
CONCLUSIONS: Low neighborhood SES is a powerful predictor of poor LTPA uptake in MI survivors, even after extensive adjustment for individual SES and baseline clinical profile. LTPA may thus represent an intermediate mechanism between neighborhood SES and post-MI outcome, which provides prevention opportunities.