NCT02648178.

Study characteristics
Methods	Setting: Medical centre, USA Recruitment: People with cancer Design: Non‐randomized single‐group assignment trial Recruitment: Clinical settings, including outpatient clinics and the infusion suite Study start date: June 2016; Study end date: May 2018
Participants	Total N: 19 Inclusion criteria: Histological or cytological diagnosis of aerodigestive tract cancers or bladder cancer within the past 5 years (more than 1 tobacco‐related malignancy is allowed) AJCC stages I ‐ IV Daily smoking (at least 10 cigarettes per day for 10 years) and breath CO2 ≥ 8 ppm Does not wish to quit smoking now (anyone wishing to quit smoking will be referred for smoking cessation counseling through the WRJ VAMC or DHMC program) May be receiving anti‐cancer agents Age 18 or older Fluent in English Patient must be capable and willing to provide informed written consent for study participation Able to participate in study visits Exclusion criteria: Cancer surgery planned in the next 9 weeks Treatment with radiation planned for the next 9 weeks Actively trying to quit smoking, or planning to in the next 30 days. (If a patient reports that they plan to quit smoking in the next 30 days, we will call them after the 30 days to see if they are still trying to quit) Any use of e‐cigarettes in the past 30 days Pregnant or trying to get pregnant Inclusion based on specific population characteristic: Patients with stage I ‐ IV aerodigestive tract cancers or bladder cancer who smoke daily 42.1% women; mean age: not reported ‐categories 18 ‐ 65 years: N = 9, > 65 years: N = 10; cpd and FTND: not reported. Motivated to quit: No (inclusion criterion) E‐cigarette use at baseline: Not specified but EC use within 30 days is an exclusion criterion
Interventions	EC: Cig‐a‐like and refillable Instructed on use of EC, and given a supply that is "approximately equivalent to their current nicotine intake". Given Halo Triton EC (leak‐proof refillable tank system) or Halo G6 leak proof prefilled cartomizers. Began participants with 18 mg/ml and moved nicotine content up or down based on participant preference. Choice of flavors, provided for 9 weeks
Outcomes	Weeks 3, 6, 9, 12. Self‐report at clinic visits Adverse events and biomarkers: Averse events assessed with a checklist for commonly‐occurring side effects from e‐cigarettes and nicotine products Exhaled carbon dioxide Expired carbon monoxide Urine propylene glycol Urine 4‐ (methylnitrosamino)‐1‐(‐3pyridyl)‐1butanol (NNAL) 40 and 1‐ hydroxy naphthalene (1‐HOP) Other outcomes measured: Timeline Follow‐Back Questionnaire (TLFB) EC appeal assessed with attitudinal ratings, on a 5‐point Likert‐type scale e‐cigarette ease of use, satisfaction, and enjoyment, and willingness to continue to purchase e‐cigarettes in the future Change in daily cigarette smoking given 10 or more E‐cig sessions Average number of E‐cigs used per day The co‐ordinators will conduct and audiorecord a 10 ‐ 15‐minute qualitative interview at 9 weeks soliciting perceptions about e‐cigarettes to be transcribed and analyzed for common themes that could be useful in developing the larger intervention urine nicotine and cotinine
Study funding	Not reported – data extracted from clinical trial registry record
Author declarations	Not reported – data extracted from clinical trial registry record
Notes	Study listed as ongoing study in the 2016 review update
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Not randomized, single‐group assignment
Allocation concealment (selection bias)	High risk	Not randomized, single‐group assignment
Incomplete outcome data (attrition bias) All outcomes	Low risk	19 enrolled; 10 participants followed up at 12 weeks
Selective reporting (reporting bias)	Unclear risk	The following measures were not reported: exhaled carbon dioxide; urine propylene glycol; urine nicotine, cotinine, NNAL and 1‐ hydroxy naphthalene (1‐HOP), and Timeline Follow‐Back Questionnaire (TLFB). Data at 6, 12 months also not reported