Secades‐Villa 2015.

Study characteristics
Methods	Study design: secondary analysis of RCT Country: Spain Data collection period: not stated Registry ID: not reported
Participants	Number of participants: N = 147 Sample characteristics (at baseline): Age (mean): CBT 43.8 years (SD 12.8), CBT+CM 43.5 years (SD 13.5); Sex (% male): CBT 44.6% (33/74), CBT+CM 32.9% (24/73) Population category: general population; Specific population: people who smoked and were seeking treatment Nicotine dependence: CBT FTND 5.4 (SD 1.8), CBT+CM 5.4 (SD 1.9); Baseline cigarettes per day: CBT 20.7 (SD 8), CBT+CM 20.2 (SD 8.4); Motivation to quit: selected by motivation to quit
Interventions	Behavioural support for smoking cessation: randomised to CBT or CBT + contingency management (CM); CBT protocol was implemented in group‐based sessions of 5 or 6 participants, for 1 hour per week for 6 weeks with quit date occurring at the 5th session; the main component was nicotine fading where from the first to the fourth week, participants were asked to gradually reduce their nicotine intake based on a weekly reduction of 30%; other components included information about tobacco, a behavioural contract, self‐monitoring and graphical representation of cigarette smoking, stimulus control, strategies for controlling nicotine withdrawal symptoms, physiological feedback (measured by CO and cotinine), training in alternative behaviours, social reinforcement of objective completion and abstinence, and relapse prevention strategies; CO and cotinine specimens were collected twice a week and participants were informed of the outcome; CM for smoking abstinence included a voucher programme in which nicotine abstinence was reinforced on an escalating schedule of reinforcement with a reset contingency ‐ points were earned for specimens testing negative for cotinine (80 ng/ml); CM for shaping abstinence included a voucher programme in which progressive reductions in cotinine (with abstinence also as the final target) were reinforced according to an individualised percentile schedule; maximum amount that participants could earn in both conditions was EUR 300 (USD 339) + points were exchangeable for vouchers with a variety of uses Pharmacological support for smoking cessation: no pharmacological support Psychotherapeutic or psychoactive support for mental health or mood: did not receive mood management
Outcomes	Definition of cessation used: self‐reported and bioverified 7‐day point‐prevalence abstinence at end of treatment, 1‐month and 6‐month follow‐up Cessation definition used for outcome(s) in this analysis: point‐prevalence abstinence Measure of biovalidation: expired CO (< 4 ppm), urine cotinine levels (< 80 ng/ml) Definition of people who continued to smoke used: exact definition not reported; missing participants at assessment period were considered non‐abstinent Time point(s) at which follow‐up was conducted: EOT, 1 month and 6 months Outcome category: Depression Outcome measure(s): Beck Depression Inventory II (BDI‐II)
Funding source	This research was supported by the Spanish Ministry of Science and Innovation Grants (PSI2011‐22804 and PSI2011‐23395) and by the Pre‐doctoral Grants BP12‐037, from the Foundation for the Promotion of Applied Scientific Research and Technology in Asturias and BES‐2012‐053988, from the Spanish Ministry of Economy and Competitiveness
Author conflicts of interest	None specified
Notes	Outcome data source: Published data