Study	Reason for exclusion
Asfar 2010	Compared delivery of quitline counselling: counsellor‐ versus participant‐initiated
Bastian 2013	Tested motivational interviewing to promote smoking cessation. Low use of NRT; only 59% of participants requested nicotine patches. Included in Lindson‐Hawley 2015 Cochrane review of motivational interviewing
Batra 2010	Experimental intervention was tailored for at‐risk subgroups, and included recommendation to use combination NRT. Standard treatment control recommended single type of NRT.
Bock 2008	Only participants interested in quitting (17% at baseline) were offered NRT. Main intervention was motivational interviewing.
Bonevski 2018	Pharmacotherapy was only offered to the participants in the intervention arm.
Borland 2008	Pharmacotherapy was only offered to participants interested in quitting; 24% reported use.
Brandon 2017	Only 3 months follow‐up
Breland 2014	Intervention delivered by computer, no personal support.
Brown 2007	Factorial trial of bupropion/placebo and mood management CBT or standard cessation CBT. Both behavioural interventions were intensive, and experimental treatment was specifically devised for people with depression.
Buchanan 2004	Only 3 months follow‐up (42 participants)
Carlin‐Menter 2011	Only 3 months follow‐up. Compared 2 versus 4 counselling callbacks for smokers calling a quitline who received up to 6 weeks of free NRT.
Chandrashekar 2015	Only 12 weeks follow‐up
Chouinard 2005	Pharmacotherapy was only offered to participants interested in quitting; 24% used.
Christenhusz 2007	Pharmacotherapy differed by arm: control arm advised to use pharmacotherapy but had to pay for it; intervention arm provided with bupropion free of charge.
Cooney 2007	Both pharmacotherapy and behavioural components varied by trial arm.
Cooper 2004	Main study results have not been published.
Costello 2011	Only 5 weeks follow‐up. Compared 2 intensities of pharmacist‐led behavioural support for participants using NRT.
Cropsey 2017	Only 12 weeks follow‐up
Cummins 2016	Control group participants may or may not have received NRT.
Dezee 2013	Only 12 weeks follow‐up
Emmons 2013	Compared web‐based versus print formats of smoking cessation intervention.
Evins 2007	Only 12 weeks follow‐up
Fang 2006	Only 3 months follow‐up
Garvey 2012a	Both behavioural interventions were of similar intensity, differing only in scheduling of sessions.
Hall 1996	Both behavioural interventions were of similar intensity.
Hall 2004	Factorial trial crossing extended behavioural support (CBT) with medical management only, and nortriptyline or placebo, for 1 year, as adjuncts to nicotine patch and 5 group counselling sessions. Placebo arms could have been compared, but no other trials confounded behavioural support with placebo, and the support common to all conditions was also much more intensive than in other trials.
Hall 2011	Similar design to Hall 2004: factorial trial crossing extended behavioural support (CBT) with medical management only, and bupropion or placebo, as adjunct to nicotine patch and 5 group support sessions over 11 weeks. As with Hall 2004, placebo arms could have been compared, but no other trials confounded behavioural support with placebo, and the support common to all conditions was also much more intensive than in other trials.
Hegaard 2003	Study population pregnant smokers, not eligible
Ingersoll 2009	Only 3 months follow‐up. Test of motivational interviewing as adjunct to nicotine patch therapy for HIV+ smokers
Japuntich 2006	Intervention was access to an internet site; no person‐to‐person behavioural support
Joseph 2004	Intervention and control did not differ on use of pharmacotherapy or intensity of behavioural support. Test of timing in relation to alcohol dependence treatment
Joyce 2008	Test of reimbursement for pharmacotherapy and counselling
Kim 2012	Pilot study of a culturally‐tailored intervention for Koreans, with only 30 participants
Kinnunen 2008	Main intervention was exercise, not eligible for this review. Recruitment to the standard care control was halted early.
Klesges 2015	Compared proactive and reactive telephone counselling. Both conditions could get same intensity of counselling.
Kotz 2009	Tested a specific behavioural intervention: feedback of biomedical information.
Levine 2010	Behavioural interventions were matched for intensity; specifically tested a weight‐related intervention.
Marshall 1985	Only offer of nicotine gum
McCarthy 2016	Only 10 weeks follow‐up
Moadel 2012	Only 3 months follow‐up
Mochizuki 2004	Only 3 months follow‐up. Small study of pharmacist advice as adjunct to NRT
NCT00781599	Only 3 months follow‐up
Nilsson 1996	Only 4 months follow‐up. Intervention was offer of group support and free NRT.
Nollen 2007	No difference in intensity of behavioural support
Nollen 2011	Only 3 months follow‐up. Study of an intervention to increase adherence to varenicline
Okuyemi 2006	All participants received same intensity of motivational interviewing, group sessions and offer of NRT. Tested different targets for motivational interviewing.
Pakhale 2015	Pharmacotherapy not offered in same way to both arms
Peckham 2015	Pharmacotherapy not offered in same way to both arms
Ramon 2013	Not all participants were offered pharmacotherapy.
Reid 2007	Intervention participants did not automatically receive additional behavioural support; intervention consisted of automated telephone calls to identify participants at risk of relapse. Only this subgroup then received further counselling.
Schnoll 2005	Only 3 months follow‐up, behavioural interventions similar in intensity as adjuncts to nicotine patch
Severson 2015	Participants were smokeless tobacco users not smokers
Shiffman 2000	Only 12 weeks follow‐up from start of treatment. Study of computer‐tailored materials as adjunct to nicotine gum
Shiffman 2001	Only 12 weeks follow‐up from start of treatment. Study of computer‐tailored materials as adjunct to nicotine patch
Sorensen 2003	Short follow‐up (preoperative period)
Strecher 2005	Only 12 weeks follow‐up from start of treatment. No personal behavioural support, study of web‐based tailored materials as adjunct to nicotine patch
Velicer 2006	Intervention was automated telephone counselling messages, no personal contact.
Vial 2002	Compared intervention from 2 different types of pharmacist, not between different intensities of support.
Ward 2001	Compared 2 group‐based behavioural interventions similar in intensity as adjuncts to nicotine patch, see Stead 2017.
Wilson 1988	Use of nicotine gum was substantially different between the relevant arms of the trial, and the intervention condition was also a test of the impact of training.
Wolfenden 2005	Only 3 month follow‐up. Test of multifaceted intervention including offer of NRT at preoperative clinics
Yu 2006	Only 12 weeks follow‐up from start of treatment
Zwar 2015	Trial of methods of delivery of care rather than of intensity of support

^{CBT: cognitive behavioural therapy
 NRT: nicotine replacement therapy}