Competitions and incentives for smoking cessation

Material or financial incentives may be used in an attempt to reinforce behaviour change, including smoking cessation. They have been widely used in workplace smoking cessation programmes, and to a lesser extent within community programmes. Quit and Win contests are the subject of a companion review.

To determine whether competitions and incentives lead to higher long-term quit rates. We also set out to examine the relationship between incentives and participation rates.

We searched the Cochrane Tobacco Addiction Group Specialized Register, with additional searches of MEDLINE (January 1966 to September 2004), EMBASE (1980 to 2004/8), CINAHL (1982 to 2004/8) and PsycINFO (1872 to 2004/6). Search terms included incentive*, competition*, contest*, reward*, prize*, contingent payment*, deposit contract*.

We considered randomized controlled trials, allocating individuals, workplaces, groups within workplaces, or communities to experimental or control conditions. We also considered controlled studies with baseline and post-intervention measures.

Data were extracted by one author and checked by the second. We contacted study authors for additional data where necessary. The main outcome measure was abstinence from smoking for at least six months from the start of the intervention. We used the most rigorous definition of abstinence in each trial, and biochemically validated rates where available. Where possible we performed meta-analysis using a generic inverse variance model, grouped by timed endpoints, but not pooled across the subgroups.

Fifteen studies met our inclusion criteria. None of the studies demonstrated significantly higher quit rates for the incentives group than for the control group beyond the six-month assessment. There was no clear evidence that participants who committed their own money to the programme did better than those who did not, or that different types of incentives were more or less effective. There is some evidence that although cessation rates have not been shown to differ significantly, recruitment rates can be improved by rewarding participation, which may be expected to deliver higher absolute numbers of successful quitters. Cost effectiveness analysis is not appropriate to this review, since the efficacy of the intervention has not been demonstrated.

Incentives and competitions do not appear to enhance long-term cessation rates, with early success tending to dissipate when the rewards are no longer offered. Rewarding participation and compliance in contests and cessation programmes may have more potential to deliver higher absolute numbers of quitters.