Do doctors' smoking habits influence their smoking cessation practices? A systematic review and meta-analysis

To assess the association between doctors' smoking status and the use of the '5As' of smoking cessation.

A systematic search of 11 databases covering English and Spanish language publications since 1996 was undertaken. Studies were included if they reported doctors' smoking status (current, former or never smoker) and rates of practising any of the 5As of smoking cessation (Ask; Advise; Assess; Assist; and Arrange). Frequencies and proportions were extracted from individual papers and risk ratios (RR) were calculated. A random-effects meta-analysis model was used to assess the effect of the doctor's personal smoking history. Covariate effects were explored using meta-regression for three pre-specified study characteristics: doctors' role, smoking prevalence of the sample and study quality.

Twenty studies were included in this systematic review. The RR of always asking patients about their smoking was not associated significantly with doctors' smoking status [RR = 0.98; 95% confidence interval (CI) = 0.94-1.02; P = 0.378; I(2)  = 0.00%; 10 studies]. Meta-analysis suggested that doctors who were current smokers had a 17% increased risk of not advising their patients to quit compared with never-smokers (RR = 0.83; 95% CI = 0.77-0.90; P < 0.000; I(2)  = 82.14%; 14 studies). However, high levels of heterogeneity were found that were not explained by the meta-regression. Regarding assisting patients to quit, never smokers were more likely to counsel than current smokers (RR = 0.92; 95% CI = 0.85-0.99; P = 0.036; I(2)  = 0.00%; three studies) but less likely to make a referral (RR = 1.40; 95% CI = 1.09-1.79; P = 0.009; I(2)  = 0.00%; five studies). No statistically significant differences were found in arranging future contact by smoking status (RR = 0.80; 95% CI = 0.52-1.23; P = 0.315; I(2)  = 47.03%; four studies).

Smoking status of doctors may affect their delivery of smoking cessation treatments to patients, with smokers being less likely than non-smokers or ex-smokers to advise and counsel their patients to quit but more likely to refer them to smoking cessation programmes.