Association between depression and worse disease-specific functional status in outpatients with coronary artery disease

Background The objective of this study was to determine if depression is associated with worse disease-specific functional status in patients with coronary artery disease. The study was designed as a cross-sectional survey and 3-month longitudinal cohort. Methods and Results The study took place in outpatient clinics of 3 Veterans Administration hospitals. All 7282 enrollees were surveyed and 4560 (62.6%) returned baseline questionnaires, including a screening instrument for depression. Thirty-nine percent (n = 1793) reported evidence of coronary artery disease and 1282 patients (71.5%) returned the Seattle Angina Questionnaire; 1025 patients (80%) completed a subsequent 3-month series of instruments. Main outcome measures used were the Seattle Angina Questionnaire, a valid, reliable, and responsive disease-specific functional status measure for patients with coronary disease, and the Mental Health Inventory, a mental health screening instrument from the Short Form-36. Mental Health Inventory evidence of depression was associated with significantly worse disease-specific functional status. Depressed patients had more physical limitation (mean difference in Seattle Angina Questionnaire score 16.9, P < .001), more frequent angina (mean difference in Seattle Angina Questionnaire score = 9.5, P < .001), less satisfaction with their treatment for coronary artery disease (mean difference in Seattle Angina Questionnaire score = 9.9, P < .001), and lower perceived quality of life (mean difference in Seattle Angina Questionnaire score = 16.3, P < .001) than nondepressed patients. Frequency of depressive symptoms demonstrated an inverse relation with cardiac-specific functional status and when patients' depression status changed over time, so did their cardiac-specific health status. Conclusions Depression is associated with significantly more physical limitation, more frequent angina, less treatment satisfaction, and lower perceived quality of life in outpatients with coronary artery disease.