Baldassarri 2018.

Study characteristics
Methods	Design: Randomized parallel‐assignment double‐blind trial Recruitment: outpatient pulmonary and primary care clinics, Tobacco Treatment Service, referrals from medical providers Setting: Hospital outpatient and primary care clinics, USA Study start date: October 2014; Study end date: June 2014
Participants	Total N: 40 N per arm: Non‐Nicotine: 20; Nicotine EC: 20 Inclusion criteria: ≥ 18 years; ≥ 1 cpd; willing to quit smoking Exclusion criteria: unstable psychiatric or medical conditions requiring hospitalization within the past 4 months; acute coronary syndromes or stroke within the past 30 days; history of allergic reactions to adhesives; women who were pregnant, nursing, or not practicing effective contraception; current use of an EC for the purpose of stopping tobacco cigarette smoking. Women: 52.5%; Mean age: 53 Mean cpd: 17 Mean FTND: 5.9; motivated to quit E cigarette use at baseline: Not reported
Interventions	EC: Refillable Both groups received standard care (8 weeks nicotine patch and counselling) and were randomized to nicotine EC or non‐nicotine EC. EC: eGO style EC (650 mAh battery, EVOD clearomizer, 3.7 V, 1.8 Ω single bottom coil), provided with e‐liquid purchased from an online vape shop (0 mg/mL or 24 mg/mL nicotine strength, 70/30 propylene glycol/vegetable glycerin, tobacco flavour); Instructed to use it as needed as a substitute for tobacco to try to satisfy cravings to smoke. If the patch alone proved adequate to prevent withdrawal and smoking cravings, the participant was advised not to use the EC. Additional EC devices, replacement coils, and liquid were provided as needed for the first 8 weeks of the study
Outcomes	Questionnaires and CO measurements taken at baseline, treatment visits at week 2, 4, 6, 8 and follow‐up at week 24 Cessation: 7‐day point prevalence abstinence, eCO ≤ 6 ppm Adverse events and biomarkers: Side effects were measured although it is unclear whether a questionnaire with prespecified symptoms was used Spirometry and FeNO at baseline and 6‐month follow‐up Other outcomes: Change in reported number of cpd at weeks 8 and 24; Change in per cent predicted FEV1 and FVC from baseline to week 24, and EC use patterns
Study funding	"Funding for this study was provided by the Yale School of Medicine, Section of Pulmonary, Critical Care, and Sleep Medicine and the National Heart, Lung, and Blood Institute grant T32HL007778. NHLBI had no role in the study design, collection, analysis, or interpretation of the data, writing the manuscript, or the decision to submit the paper for publication."
Author declarations	"Dr. Toll received a grant from Pfizer for medicine only for a research study, and he receives funding as an expert witness in litigation filed against the tobacco industry. Dr. Chupp received grants from NIH, Genetech, Glaxo Smith Kline, Astra Zeneca/Medimmune and Boston Scientific. He received consulting/speaking fees from Genetech, Astra Zeneca/Medimmune, Mannkind, and Boston Scientific. There are no other conflicts of interest for the remaining authors."
Notes	New for 2020 update. Study listed as ongoing study NCT02498145 in 2016 review update Additional data provided from authors
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “Participants were randomized using a random number generator with 1:1 blocked randomization (block size n= 8).”
Allocation concealment (selection bias)	Unclear risk	Both groups received standard care (nicotine patch and counselling) and were randomized to: nicotine EC or non‐nicotine EC (no further detail given)
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: “Treatment assignment was blinded to both the investigators and participants”
Blinding of outcome assessment (detection bias) All outcomes	Low risk	CO biochemically validated
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: “The study had a modest loss to follow‐up (20%) at week 24.” Number lost to follow‐up in each group is not reported in the paper Week 24 retention rate: Nicotine EC group: 19/20 (95%); Non‐nicotine EC group: 13/20 (65%); > 20% difference between groups
Selective reporting (reporting bias)	Low risk	Outcomes reported align with those listed in the clinicaltrials.gov record. (registered 2015; prior to study completion in 2016)