Walker 2020.

Study characteristics
Methods	Design: RCT Recruitment: National media advertising Setting: Community based, New Zealand Study start date: Recruitment between March 2016; Study end date: Aug 2018
Participants	N per arm: Patches‐only group: 125; Patches plus nicotine e‐cigarette group: 500; Patches plus nicotine‐free e‐cigarette group: 499 Inclusion criteria: Eligible if they were living in New Zealand 18 years or older smoked tobacco (amount not specified) Motivated to quit in the next 2 weeks Able to provide verbal consent Prepared to use any of the trial treatments Had access to a telephone Exclusion criteria: Pregnant or breastfeeding women Had used an e‐cigarette for smoking cessation for more than 1 week anytime in the past year Currently using smoking cessation medication Enrolled in another cessation program or study Self‐reported a history of severe allergies Poorly‐controlled asthma Cardiovascular event in the 2 weeks before enrolment Only 1 participant per household was permitted. 69% women; mean age 41.6; mean cpd 17.3; mean FTND 5.2 Motivated to quit: yes E‐cigarette use at baseline: Not reported but use of an e‐cigarette for smoking cessation for more than 1 week anytime in the past year was an exclusion criterion
Interventions	EC: Refillable Moderate‐intensity behavioral support was available for all participants immediately after randomization, then once a week for 6 weeks. This support consisted of 10 – 15 mins of withdrawal‐oriented behavioral support and advice on using their allocated treatment, delivered proactively over the phone by researchers who had received standardized training in delivery of such support. Assigned to: 1) Nicotine patch for 14 weeks including 2 week prequit. 21 mg, 24‐hr nicotine patch (Habitrol) 2) Nicotine patch and nicotine‐free EC for 14 weeks. As 1, plus 14‐week supply at no cost. A 2nd generation eVOD (Kangertech, Shenzhen GuangDong, China) starter kit, with a choice of 1 of 2 tobacco e‐liquid flavors. Advised to start using the e‐cigarette 2 weeks before their quit date, as and when necessary or desired, and in accordance with the manufacturer’s written instructions, to become familiar with its use Participants were instructed to stop smoking from their quit date and continue with their allocated treatment for 12 weeks (ad libitum use of the e‐cigarette), irrespective of any lapses to smoking 3) Nicotine patch and nicotine EC for 14 weeks. As above, but 18 mg/mL nicotine
Outcomes	Quit date, 1, 3, 6 and 12 months Continuous abstinence at 6 months with CO validation Adverse events and biomarkers: Known side‐effects associated with e‐cigarette use and nicotine patch use; SAEs Other outcomes measured: Relapse Self‐reported treatment adherence Tobacco withdrawal symptoms and urge to smoke Urge to vape Self‐reported weight Concomitant medication Treatment cross‐over Use of other smoking cessation support or medication Continued use of allocated treatment past 14 weeks Changes in shortness of breath, cough, asthma, COPD, and mental health problems Belief in ability to quit and remain tobacco‐free Smoking identity and views on their allocated treatment for smoking cessation and whether they would recommend it to other people who smoke who want to quit In people still smoking at each follow‐up call, outcomes were number of cigarettes smoked per day and reduction in smoking Participants allocated e‐cigarettes were asked about their urge to vape; whether they changed devices or e‐liquid, or both; whether they accessed any e‐cigarette support
Study funding	Funding: Health Research Council of New Zealand. "The sponsor of the study had no role in the study design, data collection, data analysis, data interpretation, or writing of the report. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit for publication."
Author declarations	NW, CB, MV, GL, ML, and VP report grants from the Health Research Council of New Zealand, during the conduct of the study. NW, CB, MV, and VP report grants from Pfizer, outside of the submitted work. GL chairs the organization End Smoking New Zealand, which advocates for harm reduction approaches to tobacco control. E‐cigarettes were purchased from a New Zealand e‐cigarette online retailer (NZVAPOR, https://www.nzvapor.com/), e‐liquid was purchased from Nicopharm, Australia (https://www.nicopharm.com.au/), and nicotine patches were supplied by the New Zealand Government via their contract with Novartis (Sydney, Australia). NZVAPOR also provided, at no cost to participants, on‐line and phone support regarding use of the e‐cigarettes. Neither NZVAPOR nor Nicopharm have links with the tobacco industry. None of the above parties had any role in the design, conduct, analysis, or interpretation of the trial findings, or writing of this publication.
Notes	Study listed as ongoing study NCT02521662 in the 2016 review update
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomization sequence
Allocation concealment (selection bias)	Low risk	Quote: “We ensured allocation concealment because the statistician who generated the random allocation was not the person randomising participants.”
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: “Participants and researchers collecting outcome data were masked to the nicotine content of the e‐liquid” but those allocated to patch only would be aware they did not have an E‐cigarette Quote: “Third, while we attempted to minimise detection bias by masking the nicotine content of the e‐liquid, we were only 30% successful, and thus some bias in favour of nicotine e‐cigarettes could have occurred.”
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Biochemical validation
Incomplete outcome data (attrition bias) All outcomes	Low risk	< 50% lost to follow‐up, similar rates of attrition between groups (within 20%)
Selective reporting (reporting bias)	Unclear risk	CO‐verified abstinence at 12 months stated as a secondary outcome but data are not reported in the main text. However, state in the appendix that too few people in each group were followed up to 12 months (36/1124) so no data are presented for this time point