Comparison of the smoking behaviour and attitudes of smokers who attribute respiratory symptoms to smoking with those who do not.

General practitioners' (GPs') advice against smoking helps smokers to stop; unfortunately, GPs cannot predict which patients will quit following advice. This postal questionnaire survey suggests that where smokers attribute their respiratory symptoms to smoking, they are eight times (95% confidence interval [CI] = 3.0-23.3) more likely to believe that their health will improve if they stop smoking and six times (95% CI = 1.4-23.3) more likely to intend to stop smoking.