While there is evidence of poor health behaviours in anxious and depressed cardiac patients, it is possible that sociodemographic factors explain these associations. Few previous studies have adequately controlled for confounders. The present study investigated health behaviours in anxious and depressed cardiac patients, while accounting for sociodemographic confounders.
A consecutive sample of 275 patients admitted to hospital after acute myocardial infarction (32%) or for coronary bypass surgery (40%) or percutaneous coronary intervention (28%) was interviewed six weeks after hospital discharge. Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale (HADS). Smoking, physical activity, alcohol intake and dietary fat intake were assessed by self-report. Backward stepwise logistic regression was used to identify the factors independently associated with anxiety and depression.
In total, 41 patients (15.2%) were 'depressed' (HADS-D ≥8) while 68 (25.2%) were 'anxious' (HADS-A ≥8). Depressed patients reported higher rates of smoking (χ2)= 4.47, p = 0.034), lower physical activity (F = 8.63, p < 0.004) and higher dietary fat intake (F = 7.22, p = 0.008) than non-depressed patients. Anxious patients reported higher smoking rates (χ2)= 5.70, p = 0.024) and dietary fat intake (F = 7.71, p = 0.006) than non-anxious patients. In multivariate analyses, an association with depression was retained for both diet and physical activity, and an association with anxiety was retained for diet. Low social support and younger age were significant confounders with depression and anxiety respectively.
While the high smoking rates evidenced in anxious and depressed patients were explained by sociodemographic factors, their poor diet and low physical activity (depressed patients only) were independent of these factors. Given the impact of lifestyle modification on survival after a cardiac event, anxious and depressed patients should be a priority for cardiac rehabilitation and other secondary prevention programmes.