Carson‐Chahhoud 2020.

Study characteristics
Methods	Country: Australia Setting: respiratory, cardiology, neurology, vascular and general medicine wards of 3 Adelaide (South Australia) hospitals Aim: to evaluate efficacy and safety of varenicline + quitline counselling vs quitline counselling alone in people admitted with smoking‐related acute illnesses Study design: phase II/III open‐label single‐blind RCT Dates conducted: August 2008‐December 2011 Study name: Smoking Termination Opportunity for inPatients (STOP)
Participants	392 adult smokers, aged 18‐75, smoking 10 CPD+, willing to quit, admitted with acute smoking‐related illnesses; randomised to varenicline + counselling (196) or counselling alone (196) Mean age 53, 32% women, 96% white, mean CPD 25, mean FTND 5.6 Exclusion criteria: standard pharmacotherapy criteria, acute or pre‐existing psychiatric illness, history of psychosis or suicidal ideation, use of varenicline in past 12 months
Interventions	Varenicline 1.0 mg x 2/d for 12 weeks, including week 1 at titrated dose (described as standard MIMS dosing schedule), + counselling Counselling only Both groups received Quit SA 5A behavioural counselling, i.e. maximum of 8 calls over 3 months. Also booklet Quit because you can, + stickers and fridge magnets. Participants had to set a TQD within first 2 weeks Contacts were attempted with all participants at days 3 and 5, weeks 1, 2, 3, 4, 12 (EoT). Additional contacts at weeks 26 and 52
Outcomes	Primary outcome: self‐reported CAR (< 5 cigarettes in total) (2 weeks‐12 months) Secondary outcomes: CAR at 4, 12 and 26 weeks. 7‐day PPA each week for first 4 weeks; craving; reduced hospital bed utilisation; reduction in healthcare costs CO validation ≤ 10 ppm used only in "a random sub‐set of subjects"
Notes	Partially funded by the Department of Respiratory Medicine, Queen Elizabeth Hospital, Adelaide, SA New for 2012 update (study ID was Smith 2012; changed for 2015 update) Author declaration of interests: "The authors have read the journal’s policy and have the following potential competing interests: KVCC was paid an honorarium and provided with economy airfares and accommodation by Pfizer Australia to present at the 2019 Smoking Exchange Summit in New South Wales where she spoke about ‘culturalspecific issues in smoking cessation’ and as an invited panellist in a plenary session about ‘a national approach to smoking cessation’. In 2017 she received an honorarium and provided with economy airfares and accommodation to speak about 12‐month results of the STOP trial at the annual Pfizer Australia conference in New South Wales, Hunter Valley. This does not alter our adherence to PLOS ONE policies on sharing data and materials. There are no patents, products in development or marketed products associated with this research to declare."
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"A pre‐defined, central, computer‐generated randomization sequence was used to assign subjects in a 1:1 ratio to either 12 weeks of treatment with varenicline plus Quitline‐counseling or 12 weeks of Quitline‐counseling alone."
Allocation concealment (selection bias)	Low risk	"using opaque, sealed envelopes with consecutive numbers"
Blinding (performance bias and detection bias) All outcomes	High risk	Open‐label design. Attempt at single‐blinding (statistical investigator). "Participants and investigators were not blinded to treatment assignment". "Randomization and allocation concealment were performed by respiratory staff independent of the study". Biochemical validation of abstinence conducted in a random subset of participants via exhaled CO levels ≤ 10 ppm
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	"Missing data from questionnaire (e.g., a question missed when administering follow‐up) were randomly imputed via a computer programme" 84% varenicline completed the study at 52 weeks, vs 82% in the placebo group
Selective reporting (reporting bias)	Unclear risk	Reuslts unavailable for some secondary outcomes prespecified in NCT record, however results may still be forthcoming in future publications