Lee 2018.

Study characteristics
Methods	Randomized parallel‐assignment double‐blind pilot trial Setting: San Francisco Veterans Affairs Medical Center (SFVAMC), USA Recruitment: veterans awaiting surgery Recruitment: In VA hospital presenting for surgery Study start date: August 2015; Study end date: May 2016
Participants	Total N: 50 N per arm: NRT: 30; END: 20 Inclusion criteria: presented to the anaesthesia preoperative clinic for elective surgery 3 or more days before surgery; currently smoked ≥ 2 CPD, having smoked at least once in the last 7 days. Exclusion criteria: exclusively used other forms of tobacco or marijuana only; pregnancy /breastfeeding; unstable cardiac condition; currently using smoking cessation pharmacotherapy; already enrolled in a smoking cessation trial; using EC on a daily basis. Inclusion based on specific population characteristic: Patients awaiting elective surgery 10% women; mean age 54; mean cpd 14; mean FTND 3.3 Motivated to quit: Not specified E‐cigarette use at baseline: Not specified but excluded daily users
Interventions	EC: Cig‐a‐like Both groups receive: i) referral to the California Smokers' Helpline, ii) brief advice lasting less than 2 minutes, iii) a brochure from the ASA about quitting smoking before surgery EC arm: 6‐week supply of NJOY e‐cigarettes (disposable, first generation). Instructed to use Bold (4.5%) ad lib for 3 weeks, then Gold (2.4%) ad lib for 2 weeks and then study (0%) ad lib for final week. Number of ECs issued corresponded to baseline cpd, assuming 1 EC = 10 cigarettes. Asked to refrain from the use of all study products at the end of 6 weeks NRT arm: 5‐week Nicoderm CQ patches, 1 week placebo patches. Dose based on cpd at baseline: ≥ 10 cpd, 21 mg/day for 3 weeks, 14 mg/day for 1 week, 7 mg/day for 1 week, 0 mg/day for 1 week. < 10 cpd at baseline: 14 mg/day for 3 weeks, 7 mg/day for 2 weeks, 0 mg/day for 1 week
Outcomes	30 Days (phone), 8 Weeks (in person), 6 Months (phone) Cessation: 7‐day PP at 30 days (not validated), 8 weeks (CO‐validated), 6 months (not validated). Smoking cessation for at least 48 hours on day of surgery (CO‐validated) Adverse events and biomarkers: Adverse events, side effects, and surgical complications by self‐report at 30 days, 8 weeks At 8 weeks exhaled CO, FEV1 and FVC Other outcomes measured: Attitudes and usage Salivary cotinine Smoking reduction
Study funding	“This work was funded by internal UCSF Department of Anesthesia and Perioperative Care funds (San Francisco, California, United States of America) and the UCSF Resource Allocation Program grant, administered by the Helen Diller Family Comprehensive Cancer Center developmental funds from the National Cancer Institute Cancer Center Support Grant (P30 CA 82103‐16). E‐cigarettes were purchased from NJOY using these funds. NJOY had no involvement in the design, execution, or analysis of the study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.”
Author declarations	“The authors declare there are no competing interests”
Notes	3 NRT participants used EC, 2 EC participants used nicotine patch Study listed as ongoing study NCT02482233 in the 2016 review update
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “Randomization was computer‐generated, with randomly permuted block sizes of 3 or 6, in a 2:1 ratio using the ralloc program”
Allocation concealment (selection bias)	Low risk	Quote: “Allocation was concealed by consecutively numbered, sealed, opaque envelopes”
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Not blinded but both interventions active with equal amounts of support so performance bias judged unlikely
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Self‐report only at 6 months and participants not blinded to condition, but similar level of support given to both groups so differential misreport judged unlikely
Incomplete outcome data (attrition bias) All outcomes	Low risk	1 NRT and 1 ENDs loss to follow‐up at 6 months
Selective reporting (reporting bias)	Low risk	All expected outcomes reported