Comparison of motivational short interventions to improve smokers’ health behaviour (the COSMOS study) – a pragmatic cluster-randomised two-arm trial in general practice

Introduction: Helping smokers to quit is an important task of general practitioners (GPs). However, achieving tobacco abstinence is difficult, and smokers who fail may still want to improve their health in other ways. Therefore, Swiss GPs developed a multithematic coaching concept that encourages health behaviour changes beyond smoking cessation alone. We compared the effectiveness of such coaching with state-of-the-art smoking cessation counselling. Methods: This study was a pragmatic cluster-randomised two-arm trial with 56 GPs in German-speaking Switzerland and 149 of their cigarette smoking patients. GPs were instructed in either multithematic health coaching or smoking cessation counselling. After 12 months, we compared their patients’ improvements in cigarette consumption, body weight, physical inactivity, alcohol consumption, stress, unhealthy diet, and a health behaviour of their own choice, using hierarchical logistic regression models and Fisher’s exact and t-Tests. Results: Over 95% of all participants achieved clinically relevant improvements in at least one health behaviour, with no difference between study arms (health coaching vs. smoking cessation counselling: aOR = 1.21, 95% CI = [0.03-50.76]; and aOR = 1.78, 95% CI = [0.51-6.25] after non-responder imputation). Rates of clinically relevant improvements in the individual health behaviours did not differ between study arms either (they were most frequent in physical activity, achieved by 3 out of 4 patients), nor did the extent of the improvements. Conclusions: Multithematic health coaching and state-of-the art smoking cessation counselling were found to be comparable interventions, both in terms of smoking cessation success and, quite unexpectedly, their effects on other health behaviours. Implications: The findings of our study suggest that in general practice, multithematic health coaching is an effective smoking cessation intervention, and conversely, monothematic smoking cessation counselling also achieves the beneficial effects of a multithematic health behaviour intervention. This opens up the possibility for GPs to support their smoking patients in improving their health behaviour in additional and more flexible ways