Predictors of smoking cessation after coronary artery bypass graft surgery. Results of a randomized trial with 5-year follow-up

Abstract

Objective: To test the efficacy of a smoking cessation program for inpatients recovering from coronary artery bypass graft surgery and to identify predictors of cessation.

Design: Randomized, controlled clinical trial.

Setting: Postoperative cardiac surgery unit of a large teaching hospital.

Patients: Patients scheduled for coronary artery bypass surgery by participating surgeons between 1 July 1986 and 1 July 1987 who had smoked 1 or more packs of cigarettes in the 6 months before admission. Of 120 eligible patients, 93 enrolled and 87 were discharged alive. All survivors were followed for at least 1 year; 94% were followed for a median of 5.5 years.

Intervention: A three-session, nurse-delivered behavior modification program using a videotape and face-to-face counseling was compared to usual care.

Measurements: Smoking status was assessed six times in the year after surgery and 5.5 years after surgery. Self-reported nonsmoking was validated by saliva cotinine assay 1 and 5.5 years after surgery.

Results: No statistically significant differences were found between control (n = 43) and intervention (n = 44) groups at baseline. One and 5.5 years after hospital discharge, validated continuous nonsmoking rates were identical in intervention and control groups (51% at 1 year; 44% at 5.5 years). Multiple logistic regression identified four factors that were independently associated with nonsmoking for 1 year: fewer than 3 previous attempts to quit (odds ratio, 7.4; 95% Cl, 1.9 to 29.1); more than 1 week of preoperative nonsmoking (odds ratio, 10.0; Cl, 2.0 to 50.2); definite intention to quit smoking (odds ratio, 12.0; Cl, 2.6 to 55.1); and no difficulty not smoking in the hospital (odds ratio, 9.6; Cl, 1.8 to 52.2). Nonsmoking for 5.5 years was independently associated with two of these factors: fewer than three previous attempts to quit and intention to quit smoking after surgery. Cessation was not related to demographic factors, daily cigarette consumption, disease severity, hospital course, social support, or beliefs and attitudes.

Conclusions: Even without specific intervention, nearly one half of smokers quit for 5 years after coronary artery bypass surgery. A short inpatient education program did not increase this rate. Future efforts should target the time after discharge and focus on increasing motivation in patients who have repeatedly failed to quit.