Effects of large financial incentives on motivation to quit smoking and on cigarette dependence

Background: Financial incentives enhance long-term smoking cessation rates, but their effects on motivation to quit in those who fail to quit are not well documented.Aim: To test the effects of large financial incentives on motivation to quit smoking and on cigarette dependence in smokers who failed to quit despite receiving incentives.Participants: Low-income smokers in the general population in Geneva, Switzerland, in 2011-2013.Methods: A randomised controlled trial with follow-up after three, six and 18 months. Participants were assigned to receive either booklets plus access to a smoking cessation website (control group, n = 404), or the same intervention plus financial incentives (intervention group, n = 401). Incremental financial rewards, to a maximum of CHF 1500 (USD 1650, GBP 1000), were offered for biochemically verified smoking abstinence. No in-person counselling, telephone counselling, or medications were provided.Measurements: Intrinsic and extrinsic motivation to quit, intention to quit, cigarette dependence.Findings: In smokers at 6-month follow-up, intrinsic motivation decreased in the control group (-0.24 SD units, p < 0.001), extrinsic motivation increased in the intervention group (+0.35 SD units, p = 0.001), and twice as many participants in the intervention group (35 %) than in the control group (17 %, p < 0.001) said they intended to quit smoking in the next 30 days. Quit attempts were more frequent and their duration was longer in the intervention group than in the control group. The intervention had no impact on cigarette dependence scores.Conclusions: Large financial incentives increased motivation to quit smoking in smokers who failed to quit smoking despite receiving incentives.