Motivational support intervention to reduce smoking and increase physical activity in smokers not ready to quit: the TARS RCT.

NHS pharmacological and behavioural support helps smokers wanting to quit, and physical activity may also help. It is unclear if behavioural support for those not ready to quit may lead to more quit attempts and abstinence from smoking. A total of 915 smokers who wanted to reduce their smoking, but who had not yet quit, were recruited and randomised to receive an intervention or brief support as usual (brief advice to quit), in Plymouth, London, Oxford and Nottingham. The intervention involved up to eight sessions (by telephone or in person) of motivational support to reduce smoking and increase physical activity (and more sessions to support a quit attempt). Participants self-reported smoking and physical activity information at the start of the trial and after 3 and 9 months. Self-reported quitters confirmed their abstinence with a biochemical test of expired air or saliva. Our main interest was in whether or not the groups differed in the proportion who remained abstinent for at least 6 months. Overall, only 1­2% remained abstinent for 6 months. Although it appeared that a greater proportion did so after receiving the intervention, because few participants were abstinent, the results are not conclusive. However, the intervention had beneficial effects on less rigorous outcomes, including a reduction in the self-reported number of cigarettes smoked, and a greater proportion of intervention than control participants with self-reported and biochemically verified abstinence at 3 months. The intervention also helped participants to reduce, by at least half, the number of cigarettes they smoked at 3 and 9 months, and to report more physical activity, but only at 3 months. Despite reasonable intervention engagement and some short-term changes in smoking and physical activity, the trial does not provide evidence that this intervention would help smokers to quit for at least 6 months nor would it be cost-effective, with an average cost of £239 per smoker.