Valentine 2018.

Study characteristics
Methods	Design: Open‐label prospective cohort study Recruitment: Recruited from within the Department of Veterans Affairs (VA) Connecticut Healthcare System by word of mouth Setting: Receiving psychiatric services from Department of Veterans Affairs healthcare system, USA Study start date/Study end date: Not specified.
Participants	Total N: 50 (sample analyzed for primary outcomes on week 1 completers – N = 43) Inclusion criteria: Without an immediate intention to stop smoking Smoking history of at least 5 cigarettes a day for the past year Exclusion criteria: Current untreated medical or psychiatric or substance use disorders, or both, as determined by a review of the veteran’s electronic medical record current use of nicotine replacement or other cessation pharmacotherapies use of e‐cigarettes or smokeless tobacco products for more than 2 of the past 30 days Inclusion based on specific population characteristic: Military veteran people who smoke who had no immediate intention to stop smoking and were currently receiving psychiatric services from the Department of Veterans Affairs healthcare system. 7% women; mean age 56.9; mean cpd 16.6; mean FTND 4.9 Motivated to quit: Had no immediate intention to stop smoking E‐cigarette use at baseline: E‐cigarettes or smokeless tobacco products may have been used for less than 2 of the past 30 days
Interventions	EC: Refillable All given eVic Supreme (Joyetech), "a commercial, variable‐power, tank‐type device". 6.5 mL tank (Delta 23, Joyetech) and a C3 triple coil atomizer head (Joyetech) with a total resistance of 1.8 ohms. Participants could choose flavor (menthol or tobacco) and nicotine concentration (12 or 24 mg/mL). Participants taught how to use EC, with additional materials dispensed as needed. Participants were informed that they could use the study e‐cigarette or regular tobacco cigarettes, or both, ad libitum during study participation
Outcomes	Week 1, 2, 3, 4, 8 (Weekly lab visits and 1 month follow‐up) Adverse events and biomarkers: Alveolar (breath) CO levels (ppm) Other outcomes measured: Number of cpd The frequency of e‐cigarette use (mean days/week) The amount of money spent on combustible cigarettes (US dollars/week) Fagerström Test of Nicotine Dependence Contemplation Ladder E‐cigarette questionnaire (assessed changes in perceptions about e‐cigarettes (e.g. harmfulness, benefits, cost), motivations to use (or not use) them, and the reasons for e‐cigarette or combustible cigarette preferences) (measured at baseline and follow‐up) Cotinine
Study funding	"This research was supported by the New England Mental Illness Research, Education and Clinical Center and the U.S. Department of Veterans Affairs. Statistical analyses, biochemical assays, and analyses of e‐cigarette solutions were supported by the Administrative and Laboratory cores of P50DA036151 (Yale TCORS) from the National Institutes of Health and the U.S. Food and Drug Administration Center for Tobacco Products. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or of the U.S. Food and Drug Administration."
Author declarations	"Ralitza Gueorguivea, PhD, discloses consulting fees for Palo Alto Health Sciences and Mathematica Policy Research and a provisional patent submission by Yale University: Chekroud, A. M., Gueorguieva, R., & Krystal, K. H. “Treatment Selection for Major Depressive Disorder” (filing date June 3, 2016, USPTO docket number Y0087.70116US00). The authors report no other financial relationships with commercial interests."
Notes	New for 2020 update.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Uncontrolled cohort study
Allocation concealment (selection bias)	High risk	Uncontrolled cohort study
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Follow‐up: 31/50 at week 8
Selective reporting (reporting bias)	Unclear risk	No protocol or clinical trial record.