Pulvers 2018.

Study characteristics
Methods	Design: Observational uncontrolled experimental study Recruitment: Community Setting: Visits took place in University labs, USA Study start date: January 2015; Study end date: April 2015
Participants	Total N: 40 Inclusion criteria: Being 18 years of age or older Cigarette smoking on at least 4 days of the past 30 days for at least 1 year Never using EC regularly (less than 25 lifetime uses) Not having used EC on more than 3 of the past 30 days Being willing to switch from smoking regular cigarettes to ECs Fluency in English Having regular access to a telephone and transportation to attend appointments Being willing to abstain from using marijuana during the study Exclusion criteria: Any use of other tobacco products (OTPs) including smokeless tobacco, cigarillos, pipes, cigars, hand‐rolled cigarettes, and hookah in the past 30 days Being currently in a smoking cessation programme or another clinical trial Past 30 day use of nicotine replacement therapy or medication which aids smoking cessation including bupropion, clonidine, nortriptyline, or varenicline Having uncontrolled asthma, severe allergies, or diabetes mellitus Currently taking prescription medication for emotional distress, depression, or other psychological problems Current dependence on a substance other than nicotine Presence of any cardiovascular or pulmonary illnesses in the past 6 months For women, pregnancy or plans to become pregnant in the next 6 months Inclusion based on specific population characteristic: No 27% women; mean age 30.08; mean cpd 8.76; FTND not reported Motivated to quit: over half either did not intend to quit at all or did not intend to quit in the next 6 months 22/40 (55%) E‐cigarette use at baseline: Inclusion criteria included the following: Never using EC regularly (less than 25 lifetime uses) Not having used EC on more than 3 of the past 30 days
Interventions	EC: Refillable 2nd generation EC starter kit with 2 e‐Go C batteries (3.7 volts/650 MaH), a USB connection cord, an AC adapter, and a carrying case, and a supply of Saturn V4i atomizers (2.4 ohms) filled with liquid in their preferred flavour (28 atomizers total; 2/day). Provided 24 mg/mL dosage vegetable glycerin liquid in a tester sample to all participants. Those who reported the 24 mg was too strong were provided 12 mg/mL dosage liquid. The first session included brief education, training, action planning for making a complete switch to EC. A referral to the California Smokers’ Helpline was made at the final visit (week 4).
Outcomes	3 lab visits (baseline, week 2, and week 4) and 2 phone visits (week 1 and week 3). Biological samples were taken at all 3 in‐person visits (baseline, week 2, and week 4). However, due to budgetary restrictions, only the baseline and week 4 biological data were analysed Adverse events and biomarkers: Biochemical measures only: Breath samples were taken with a Micro + (Bedfont, Haddonfield, NJ) to measure CO Urine samples taken to test for change in tobacco toxicant exposure by following measures: concentrations of NNAL measured by liquid chromatography–tandem mass spectrometry (LC–MS/MS) metabolites of a panel of potentially toxic VOCs, including benzene (PMA), ethylene oxide (HEMA), N‐nitrosodimethylamine (MMA), acrylonitrile (CNEMA), acrolein(3‐HPMA), propylene oxide (2‐HPMA), acrylamide (AAMA), and crotonaldehyde (HPMMA) measured by LC–MS/MS,2 Other outcomes measured: Cotinine, change in tobacco consumption (CPD using TLFB interview), change in frequency of EC use, change in nicotine dependence and attitudes/behaviour, change in 30‐day nicotine exposure
Study funding	“This study was funded by the University of Minnesota (JSA), P30 DA012393 (NLB), P50 CA180890 (NLB), and California State University San Marcos (KP).”
Author declarations	“Benowitz is a consultant to pharmaceutical companies that market smoking cessation medications and has been an expert witness in litigation against tobacco companies. The other authors have no conflicts of interest.”
Notes	New for 2020 update
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Not randomized
Allocation concealment (selection bias)	High risk	Not randomized
Incomplete outcome data (attrition bias) All outcomes	Low risk	37/40 provided follow‐up data
Selective reporting (reporting bias)	Low risk	All outcomes reported