Prochaska 2014

Methods	Design: Prospective observational study using data from a 3‐group randomized RCT Recruitment: 2009 ‐ 2013, recruited as part of clinical trial of smokers with serious mental illness Setting: Inpatient psychiatric hospital, California, USA Inclusion criteria: Daily smokers of 5+ cpd, patient at 100% smoke‐free acute care unit at psychiatric hospitals Exclusion criteria: non‐English speaking; medical contraindications to NRT use (pregnancy, recent myocardial infarction); and lack of capacity to consent as determined by a 3‐item screener of study purpose, risks, and benefits
Participants	Total N: 956 UC 134 Brief treatment 414 Extended treatment 408 50% women; mean age 39; 15% Hispanic, 57% white, 24% African‐American, 5% Asian/Pacific Islander; 14% multiracial/other; mean cpd 17; 11% used EC at baseline, 24% intended to quit smoking in next month Psychiatric diagnoses were 27% unipolar depression, 32% bipolar depression, and 27% nonaffective psychotic disorder; other (14%). 68% met criteria for alcohol or illicit drug abuse or dependence
Interventions	RCT tested levels of behavioural support: Usual care; brief treatment; extended treatment. Treatment groups received tailored computer‐assisted intervention or on‐unit counselling. Extended group offered 10 sessions of CBT No significant differences in EC use by treatment group. All participants were provided NRT following hospitalization (3 months brief arm, 6 months extended arm)
Outcomes	Follow‐up at 3, 6, 12, 18m. This paper reports “latest follow‐up” Cessation measured but definition not described Cpd
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Observational for purpose of this analysis
Allocation concealment (selection bias)	High risk	Observational for purpose of this analysis
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Although there is no blinding, the study design means that there is unlikely to be significantly impact on performance by EC use at baseline
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not clear how outcome measures were assessed
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Follow‐up for larger RCT still ongoing, unclear what percentage of participants eligible for this analysis were followed up
Selective reporting (reporting bias)	Low risk	All expected outcomes reported