Living alone, patient sex and mortality after acute myocardial infarction.

BACKGROUND

Psychosocial factors, including social support, affect outcomes of cardiovascular disease, but can be difficult to measure. Whether these factors have different effects on mortality post-acute myocardial infarction (AMI) in men and women is not clear.

OBJECTIVE

To examine the association between living alone, a proxy for social support, and mortality postdischarge AMI and to explore whether this association is modified by patient sex.

DESIGN

Historical cohort study.

PARTICIPANTS/SETTING: All patients discharged with a primary diagnosis of AMI in a major urban center during the 1998-1999 fiscal year.

MEASUREMENTS

Patients' sociodemographic and clinical characteristics were obtained by standardized chart review and linked to vital statistics data through December 2001.

RESULTS

Of 880 patients, 164 (18.6%) were living alone at admission and they were significantly more likely to be older and female than those living with others. Living alone was independently associated with mortality [adjusted hazard ratio (HR) 1.6, 95% confidence interval (CI) 1.0-2.5], but interacted with patient sex. Men living alone had the highest mortality risk (adjusted HR 2.0, 95% CI 1.1-3.7), followed by women living alone (adjusted HR 1.2, 95% CI 0.7-2.2), men living with others (reference, HR 1.0), and women living with others (adjusted HR 0.9, 95% CI 0.5-1.5).

CONCLUSIONS

Living alone, an easily measured psychosocial factor, is associated with significantly increased longer-term mortality for men following AMI. Further prospective studies are needed to confirm the usefulness of living alone as a prognostic factor and to identify the potentially modifiable mechanisms underlying this increased risk.