Pilot Study of Contingency Management for Smoking Cessation

The study aims to investigate whether a contingency management (CM) intervention can be added to usual NHS stop smoking services (SSS) treatment, in patients undergoing treatment for opiate addiction.

The SSS at the treatment centre follows the standard treatment program set out by the National Centre for Smoking Cessation and Training (NCSCT) and the NICE guidelines for smoking cessation. Service users taking part in the SSS attend one meeting per week for six weeks. In the first meeting with a cessation worker the client completes baseline information about the client's age, gender, ethnicity, employment, motivation to quit, past quit attempts and current smoking behaviour), and sets a quit date for the following week. For the remaining four weeks clients attend the clinic to receive behavioural support. Nicotine replacement therapy (NRT) is available free of charge to all individuals engaged with SSS. During the six weeks of treatment, service users are given a week's supply of NRT at a time. At the end of the six weeks, service users are given a two week supply of NRT before exiting the SSS treatment. NRT use is recorded throughout SSS treatment. Clients' breath carbon monoxide (CO) levels are also measured at the initial visit and at each subsequent visit over the next 5 weeks in order to biochemically verify self-reported abstinence from smoking (CO<10ppm).

The CM intervention that this study will run as an adjunct to the SSS,. The 40 participants will be randomised into either experimental (CM for abstinence) or control (CM for attendance) conditions at intake. Randomisation will be stratified based on participants' current smoking frequency (between 10 and 20 per day, and more than 20 per day). The intervention will run for five weeks in total, with randomisation occurring at visit 1, and the intervention beginning in week two of the SSS treatment and ending in week six. Participants will be rewarded for smoking abstinence in the experimental condition, and for attending the SSS clinic in the control condition. For the experimental condition smoking abstinence will be defined as a breath CO reading of <10ppm, and for the control condition attendance will be defined as attending the SSS clinic once a week. Rewards will be administered by a researcher to ensure cessation workers are not aware of group allocation.

The intervention will employ an 'escalating with reset' schedule, Reward values will be the same in both conditions. In escalating with reset CM, rewards escalate in a set increment value for each successive verified display of the desired behaviour. When the desired behaviour is not observed, no reward is given, and the reward value for the next verified display of the desired behaviour is reset to that of the initial reward. Reward values then begin to rise again in the same way as before.

Six months after their set quit date, participants will be contacted by the PI to ascertain their self-reported smoking status. In order to test the optimal follow up method, participants will be pseudo-randomised to be contacted by text and phone call, or email and phone call. All participants will also be asked to return to the clinic in order to have their breath CO levels tested to verify this. Once this is done, participants will have completed their participation in the study.