Context Little is known regarding the extent to which patient-reported health
status, including symptom burden, physical limitation, and quality of life,
is determined by psychosocial vs physiological factors among patients with
Objective To compare the contributions of depressive symptoms and measures of
cardiac function to the health status of patients with coronary artery disease.
Design, Setting, and Participants Cross-sectional study of 1024 adults with stable coronary artery disease
recruited from outpatient clinics in the San Francisco Bay Area between September
2000 and December 2002.
Main Measures Measurement of depressive symptoms using the Patient Health Questionnaire
(PHQ); assessment of cardiac function by measuring left ventricular ejection
fraction on echocardiography, exercise capacity on treadmill testing, and
ischemia on stress echocardiography; and measurement of a range of health
status outcomes, including symptom burden, physical limitation, and quality
of life, using the Seattle Angina Questionnaire. Participants were also asked
to rate their overall health as excellent, very good, good, fair, or poor.
Results Of the 1024 participants, 201 (20%) had depressive symptoms (PHQ score
≥10). Participants with depressive symptoms were more likely than those
without depressive symptoms to report at least mild symptom burden (60% vs
33%; P<.001), mild physical limitation (73% vs
40%; P<.001), mildly diminished quality of life
(67% vs 31%; P<.001), and fair or poor overall
health (66% vs 30%; P<.001). In multivariate analyses
adjusting for measures of cardiac function and other patient characteristics,
depressive symptoms were strongly associated with greater symptom burden (odds
ratio [OR], 1.8; 95% confidence interval [CI], 1.3-2.7; P = .002), greater physical limitation (OR, 3.1; 95% CI, 2.1-4.6; P<.001), worse quality of life (OR, 3.1; 95% CI, 2.2-4.6; P<.001), and worse overall health (OR, 2.0; 95% CI,
1.3-2.9; P<.001). Although decreased exercise
capacity was associated with worse health status, left ventricular ejection
fraction and ischemia were not.
Conclusions Among patients with coronary disease, depressive symptoms are strongly
associated with patient-reported health status, including symptom burden,
physical limitation, quality of life, and overall health. Conversely, 2 traditional
measures of cardiac function—ejection fraction and ischemia—are
not. Efforts to improve health status should include assessment and treatment
of depressive symptoms.