NCT02918630.

Study characteristics
Methods	Design: RCT Recruitment: Clinics Setting: SMI clinics, USA Study start date: October 2016; Study end date: August 2017
Participants	Total N: 7 N per arm: NRT: 4; EC+NRT 3 Inclusion criteria: Be diagnosed with schizophrenia (or other SMI, not clear) Be in stable medical condition (DSM‐V) Report smoking ≥ 10 tobacco cigarettes/day Present a breath CO ≥ 10 ppm Report wanting to reduce their cigarette smoking Be fluent in English Have a stable living situation Exclusion criteria: Be currently pregnant or breastfeeding Report wanting to quit smoking in the immediate future Test positive for illicit drugs except THC Have any illness, medical condition, or use of medications, which in the opinion of the study physicians would preclude safe or successful completion of the study, or both Inclusion based on specific population characteristic: Yes ‐ SMI (schizophrenia and schizoaffective disorder, bipolar disorder, or PTSD) 43% women; mean age 48.3; mean cpd: NR; mean FTND: NR Motivated to quit: Wanted to quit or reduce their cigarette smoking but did not want to quit in the immediate future (this was an exclusion criterion) NB – trial registry states wanted to reduce and protocol states wanted to quit or reduce as inclusion criteria E‐cigarette use at baseline: Not specified
Interventions	EC: Refillable Both arms received a nicotine patch 21 mg for 4 weeks EC + NRT: 4 weeks: 1) a 3.3 V, 1000 mAh battery; and 2) a 1.5 Ohm, dual‐coil cartomizer (SmokTech; Shenzhen, China). Nicotine concentrations 36 mg/ml. Verbal and written instructions on how to use and maintain the e‐cigarettes at Week 1 visit NRT arm: NRT only
Outcomes	5 weeks Cessation: n/a but “change in smoking” Adverse events and biomarkers: Breath CO, COPD‐related symptoms, EC side effects (e‐cig side effects questionnaire), AEs, SAEs Other outcomes measured: Urinary cotinine, cpd, tobacco dependence, craving, withdrawal symptoms, desire to quit, confidence to quit, EC dependence, EC use, satisfaction with EC, nicotine dependence, schizophrenia symptoms (brief psychiatric rating scale), cognitive domains associated with schizophrenia (MATRICS consensus cognitive battery), changes in positive symptoms of schizophrenia (scale for the assessment of positive symptoms), changes in negative schizophrenia symptoms (scale for the assessment of negative symptoms), suicide ideation (Columbia Suicide Severity Rating Scale)
Study funding	Not reported
Author declarations	Not reported
Notes	New for 2020 update. Information from http://clinical trials gov registry and unpublished protocol; discrepancies between the two in terms of trial methods. Feasibility for future NIH grant application. Intended to recruit 20 participants but only 7 started and completed
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	“double‐blind” but “open‐label” elsewhere, no further info given
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not reported
Selective reporting (reporting bias)	High risk	Schizophrenia and COPD outcomes not reported.
Other bias	Unclear risk	Some discrepancies between clinicaltrials record and protocol linked to from record, including when NRT started and inclusion criteria (just schizophrenia or all SMI). Target sample size was 20 but only 7 people recruited