Systematic review and meta-analysis of the impact of depression on subsequent smoking cessation in patients with coronary heart disease: 1990 to 2013.

Objective: Smoking cessation is crucial for patients with coronary heart disease (CHD), yet depression may impede cessation success. We systematically reviewed the prospective association between depression and subsequent smoking cessation in individuals with CHD to quantify this effect.

Methods: Electronic databases (PsychInfo, PubMed, CINAHL) were searched for prospective studies of patients with CHD that measured depression at baseline (scales, diagnostic interview, or antidepressant prescription) and reported smoking continuation/cessation at follow-up. Inclusive dates were January 1, 1990, to May 22, 2013. Standardized mean differences (SMDs) and associated 95% confidence intervals were estimated using random-effects meta-analysis. Sensitivity analysis explored the impact of limiting meta-analysis to studies using different depression measures (validated scales, diagnostic interviews, antidepressant prescription), different durations of follow-up, or higher-quality studies.

Results: From 1185 citations retrieved, 28 relevant articles were identified. Meta-analysis of all available data from 20 unique data sets found that depressed patients with CHD were significantly less likely to quit smoking at follow-up (SMD = -0.39, 95% confidence interval = -0.50 to -0.29; I(2) = 51.2%, p = .005). Estimates remained largely unchanged for each sensitivity analysis, except for two studies that used antidepressants, which showed a much larger effect (SMD = -0.94, -1.38 to -0.51; I(2) = 57.7%, p = .124).

Conclusions: Patients with CHD and depressive symptoms are significantly less likely to quit smoking than their nondepressed counterparts. This may have implications for cardiovascular prognosis, and CHD smokers may require aggressive depression treatment to enhance their chances of quitting.