title: Identifying effective behavioural components of Intervention and Comparison group support provided in SMOKing cEssation (IC-SMOKE) interventions: a systematic review protocol.
abstract: BACKGROUND
  Systematic reviews of behaviour change interventions for smoking cessation vary in scope, quality, and applicability. The current review aims to generate more accurate and useful findings by (1) a detailed analysis of intervention elements that change behaviour (i.e. behaviour change techniques (BCTs)) and potential moderators of behaviour change (i.e. other intervention and sample characteristics) and (2) assessing and controlling for variability in support provided to comparison groups in smoking cessation trials.
  
  
  METHODS
  A systematic review will be conducted of randomized controlled trials of behaviour change interventions for smoking cessation in adults (with or without pharmacological support), with a minimum follow-up of 6 months, published after 1995. Eligible articles will be identified through the Cochrane Tobacco Addiction Group Specialized Register. Study authors will be asked for detailed descriptions of smoking cessation support provided to intervention and comparison groups. All data will be independently coded by two researchers. The BCT taxonomy v1 (tailored to smoking cessation interventions) and template for intervention description and replication criteria will be used to code intervention characteristics. Data collection will further include sample and trial characteristics and outcome data (smoking cessation rates). Multilevel mixed-effects meta-regression models will be used to examine which BCTs and/or BCT clusters delivered to intervention and comparison groups explain smoking cessation rates in treatment arms (and effect sizes) and what key moderators of behaviour change are. Predicted effect sizes of each intervention will be computed assuming all interventions are compared against comparison groups receiving the same levels of behavioural support (i.e. low, medium, and high levels). Multi-disciplinary advisory board members (policymakers, health care providers, and (ex-)smokers) will provide strategic input throughout the project to ensure the review's applicability to policy and practice.
  
  
  CONCLUSIONS
  By capturing BCTs in intervention and comparison groups, this systematic review will provide more accurate estimates of the effectiveness of smoking cessation interventions, the most promising BCTs and/or BCT clusters associated with smoking cessation rates in intervention and comparison arms, and important moderators of behaviour change. The results could set new standards for conducting meta-analyses of behaviour change interventions and improve research, service delivery, and training in the area of smoking cessation.
  
  
  BACKGROUND
  PROSPERO CRD42015025251.
authors.affiliation: Aberdeen Health Psychology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, Scotland. m.debruin@abdn.ac.uk.
authors.forename: Marijn
authors.initials: M
authors.lastname: de Bruin
authors.affiliation: Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Viechtbauer
authors.affiliation: Aberdeen Health Psychology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, Scotland.
authors.forename: Maarten C
authors.initials: MC
authors.lastname: Eisma
authors.affiliation: Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, England.
authors.forename: Jamie
authors.initials: J
authors.lastname: Hartmann-Boyce
authors.affiliation: Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, England.
authors.forename: Robert
authors.initials: R
authors.lastname: West
authors.affiliation: NHS Grampian Public Health Directorate, Aberdeen, Scotland.
authors.forename: Eleanor
authors.initials: E
authors.lastname: Bull
authors.affiliation: Research Department of Clinical, Educational and Health Psychology, University College London, London, England.
authors.forename: Susan
authors.initials: S
authors.lastname: Michie
authors.affiliation: Aberdeen Health Psychology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, Scotland.
authors.forename: Marie
authors.initials: M
authors.lastname: Johnston
mesh_terms: D001521:Behavior Therapy / Q000379:methods*; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D012907:Smoking / Q000628:therapy*; D016540:Smoking Cessation / Q000379:methods*; D000078202:Systematic Reviews as Topic; D014029:Tobacco Use Disorder / Q000628:therapy*
keywords: Behaviour change technique; Comparison group; Control group; Intervention; Meta-analysis; Meta-regression; Randomized controlled trial; Smoking cessation; Systematic review; Tobacco