Pulvers 2020.

Study characteristics
Methods	Design: RCT. Unblinded. 2:1 ratio Recruitment: Participants were recruited from the San Diego, California, and Kansas City, Missouri and Kansas, metropolitan areas Setting: USA Study start date: May 2018. Study end date: May 2019
Participants	Total N = 186; Electronic‐cigarettes = 125. Own brand cigarette = 61 40.3% female; mean age 43.3 (SD 12.5); mean cpd 12.1 (SD 7.2). E‐cigarettes use at baseline: 0.05 (0.3%) Inclusion criteria: > 21 years of age; smoked cigarettes on > 25 of past 30 days; smoked > 5 cpd on days smoked; smoked cigarettes > 6 months; carbon monoxide > 5 PPM at baseline; systolic BP of < 160 mmHg and diastolic BP of < 105 mmHg at baseline; Hispanic/Latino or African‐American/Black; fluent in English or Spanish; willing to switch from smoking cigarettes to ECs for 6 weeks; regular access to telephone; transportation to attend appointments (KC Only). Exclusion criteria: primary use of other tobacco products or equal use of cigarettes and other tobacco products; EC use on > 4 of the past 30 days; currently in a smoking cessation programme or another clinical trial; use of NRT or medication which aids smoking cessation in the past 30 days; hospitalization for a psychiatric issue in the past 30 days; heart‐related event in the past 30 days (e.g. heart attack, stroke, severe angina (i.e. chest pain), ischaemic heart disease, and vascular disease); uncontrolled blood pressure; planning to move out of study centres (San Diego or Kansas City) in the next 6 wks; another person in the household enrolled in the study; pregnancy / breastfeeding; unstable mental status or health status.
Interventions	EC: pod Electronic‐cigarettes: JUUL (5% nicotine); Choice of flavors (Menthol, Mango, Cool Mint, Virginia Tobacco); Given 1 pod per pack of cigarettes; Given a 2‐week supply at baseline and then a further 4‐week supply at week‐2 visit. At each follow‐up appointment (week 1, telephone call; week 2, in‐person visit; and week 4, telephone call), barriers and benefits of switching to e‐cigarette were discussed and action planning for exclusive switching was revisited. Compensated on a schedule of USD 20 at baseline, USD 40 at week 2 and USD 60 at week 6 Own brand cigarettes: Compensated on a schedule of USD 20 at baseline, USD 40 at week 2 and USD 60 at week 6
Outcomes	Baseline, week 2 and week 6. Telephone survey at 6 months Change in past 7‐day combustible cigarette use measured by 7‐day timeline follow‐back interview 30‐day point prevalence at 6 months (EC group only) reduction in toxicant exposure, as measured by NNAL excretion. Cotinine CO Lung function; Pulmonary function test of small airway disease that is most sensitive to effects of cigarette smoking; mean mid‐expiratory phase of forced expiratory (FEF 25%‐75%); respiratory symptoms as measured with the American Thoracic Society Questionnaire (scores range from 0‐32, with higher scores indicating greater respiratory symptoms) Blood pressure Adverse events: respiratory symptoms
Study funding	Drs Pulvers and Nollen and Ms Rice were supported by grant No. 5SC3GM122628 from the National Institutes of Health (NIH). Drs Schmid and Ahluwalia were supported in part by grant No. P20GM130414, from the NIH‐funded Center of Biomedical Research Excellence (COBRE). Dr Schmid was partially supported by Institutional Development Award No. U54GM115677 from the National Institute of General Medical Sciences of the NIH, which funds Advance Clinical and Translational Research (Advance‐CTR)
Author declarations	Dr Schmid reported serving as a consultant for legal firms representing Eli Lilly, Boehringer‐Ingelheim, and Gilead outside the submitted work. Dr Benowitz reported receiving personal fees from Pfizer and Achieve Life Sciences and serving as a consultant to pharmaceutical companies that market smoking cessation medications and as an expert witness in litigation against tobacco companies outside the submitted work. Dr Ahluwalia reported receiving personal fees from Lucy Goods outside the submitted work. No other disclosures were reported.
Notes	Additional data provided by authors
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomization sequence was generated with an Excel (Microsoft) random number formula applied to each site (2:1 ratio)
Allocation concealment (selection bias)	Low risk	Allocation was placed into sealed individual envelopes labelled with participant identification numbers for each site, retrieved from a locked cabinet monitored by the project manager, and opened individually following consent of each participant
Blinding of participants and personnel (performance bias) All outcomes	High risk	Could not be blinded
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Carbon monoxide validation
Incomplete outcome data (attrition bias) All outcomes	Low risk	E‐cig: 115/126 OB: 54/61
Selective reporting (reporting bias)	Low risk	Per protocol reporting