Objective: To evaluate the hypothesis that diminished social and economic resources impact adversely on cardiovascular mortality in patients with coronary artery disease.
Design: Inception cohort study of patients undergoing cardiac catheterization from 1974 through 1980 and followed up through 1989.
Setting: Tertiary care university medical center.
Patients: Consecutive sample of 1965 medically treated patients with stenosis 75% or greater of at least one major coronary artery. Five hundred patients were not enrolled due to logistic problems; 33 refused; 64 had missing data on key medical variables. The final study population included 1368 patients, 82% male, with a median age of 52 years.
Main outcome measure: Survival time until cardiovascular death.
Results: Independent of all known baseline invasive and noninvasive medical prognostic factors, patients with annual household incomes of $40,000 or more had an unadjusted 5-year survival of 0.91, compared with 0.76 in patients with incomes of $10,000 or less (Cox model adjusted hazard ratio, 1.9; 95% confidence interval, 1.57 to 2.32; P = .002). Similarly, unmarried patients without a confidant had an unadjusted 5-year survival rate of 0.50, compared with 0.82 in patients who were married, had a confidant, or both (adjusted hazard ratio, 3.34; 95% confidence interval, 1.84 to 6.20; P less than .0001).
Conclusions: Low levels of social and economic resources identify an important high-risk group among medically treated patients with coronary artery disease, independent of important medical prognostic factors. Additional study will be required to see if interventions to increase these resources improve prognosis.