Zincir 2013.

Study characteristics
Methods	Study design: RCT Country: Turkey Setting: outpatient SC clinic in a hospital Recruitment method: patients who presented at the SC outpatient clinic were included in the study on a voluntary basis
Participants	300 participants randomised; average age: 45.8 in those who stopped smoking and 40.8 in those who continued smoking; average boxes of cigarettes per year: 23.62 in those who stopped smoking and 23.26 in those who continued smoking; mean FTND: 5.9 in those who stopped smoking and 6.7 in those who continued smoking
Interventions	Bupropion 150 mg/day, started a week before the quit day and continued from day 1‐3, raised to 300 mg daily on day 4, with this dose maintained until the end of week 12 Varenicline 0.5 mg daily, raised to 1 mg daily at day 4, then to 2 mg daily at day 8, with this dose maintained until the end of week 12 NRT: administered using either a nicotine patch or nicotine gum, or a combination of both. Nicotine patches were used in their 3 forms containing 21, 14 and 7 mg of nicotine, and in cases of excessive nicotine craving, 2 mg nicotine gum was used. For each dose of nicotine patches, 4 weeks of administration in decreasing doses was recommended. The nicotine gum was started between 12 and 24 doses (2 mg) a day and gradually decreased.
Outcomes	SC: definition not specified; measured at 24‐28 weeks from study start AEs: measured for unspecified period
Notes	Funding: not reported Author declaration of interests: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: “…they were randomized to the pharmacological therapy groups” Comment: no further information given
Allocation concealment (selection bias)	Unclear risk	Quote: “…they were randomized to the pharmacological therapy groups" Comment: no further information given
Blinding (performance bias and detection bias) All outcomes	High risk	Quote: “This was a naturalistic clinical follow‐up study." Comment: those involved in the study were therefore unblinded
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	300 participants were randomised and 251 completed the study. Therefore 49/300 (16.3%) were lost to follow‐up overall. However, it is impossible to establish the number lost to follow‐up by group.
Selective reporting (reporting bias)	Unclear risk	Protocol unavailable
Other bias	High risk	Quote: “no adverse event was reported during the study”. This is highly unlikely to be correct when considering standard definitions of AEs. There is no explanation of how AEs were assessed in this study. In addition, the wording of the paper makes the final follow‐up slightly unclear. After discussion we judged final follow‐up to be 24‐28 weeks from study start, although quit rates are higher than would be expected at this time point.

AE: adverse event; BMI: Body Mass Index (kg/m²); CA: continuous abstinence; CAR: Continuous Abstinence Rate; cNRT: combined nicotine replacement therapy; CO: carbon monoxide; COPD: chronic obstructive pulmonary disease; CPD: cigarettes per day; CQR: continuous quit rate; CVD: cardiovascular disease; DSM‐IV:Diagnostic and Statistical Manual of Mental Disorders, 4th Edition; ECG: electrocardiogram; EoT: end of treatment; FTND: Fagerström Test for Nicotine Dependence; ITT: intention‐to‐treat; LOCF: last observation carried forward; MA: meta‐analysis; MDD: major depressive disorder; MI: motivational interviewing; MIMS: Monthly Index of Medical Specialities; mCEQ: Modified Cigarette Evaluation Questionnaire; MNWS: Minnesota Nicotine Withdrawal Scale; NCT: National Clinical Trials (ClincialTrials.gov registry); NRT: nicotine replacement therapy; PA: prolonged abstinence; PPA: point‐prevalence abstinence; ppm: parts per million; QoL: quality of life; QSU‐brief: Brief Questionnaire of Smoking Urges; RCT: randomised controlled trial; SAE: serious adverse event; SC: smoking cessation; TQD: target quit date