Davis 2011.

Methods	Study design: RCT Location: USA Setting: laboratory Recruitment: precontemplative and contemplative smokers were recruited from the community through advertisements and direct recruitment (no further explanation). Participants were offered USD 25 for participation.
Participants	Defining eligibility criteria?: unmotivated adult smokers Participant characteristics: 218 adult smokers randomised to intervention (109) and control (109), 45% female; mean age 37.6. cpd: 25.4 Motivation to quit?: not motivated
Interventions	Control: Prescriptive 15‐min interview regarding smoking. Described as the current dominant approach (i.e. usual care), which maintains a firm and authoritative approach Intervention: 15‐min motivational interview regarding smoking. Motivational interviewing described as seeking to establish supportive and empathic alliance Provider: nurses Intensity: 1 x 15‐minute session Was MI fidelity monitored?: "All tapes were reviewed for adherence to the protocol and weekly meetings were held with the study nurses. Sessions not reaching criterion were removed from the analyses".
Outcomes	Definition of cessation used: point prevalence Length of longest follow‐up: 6 months Validation: urinary cotinine Was mental health and/or well‐being measured at follow‐up?: no Was quality of life measured at follow‐up?: no
Funding source	A grant from The Arizona Disease Control Research Commission
Author conflicts of interest	Not reported
Notes	The outcome used for meta‐analysis was point prevalence reported at both 1 m and 6 m (i.e. cross between point prevalence and prolonged abstinence). This outcome was used as for all others, the manner of reporting made it impossible to tell which time point numbers referred to (i.e. abstinent at 1 m or 6 m).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	QUOTE: "participants completed informed consent, baseline assessments, and were randomized to receive either a 15‐min motivational or prescriptive interview". No further information given
Allocation concealment (selection bias)	Unclear risk	QUOTE: "participants completed informed consent, baseline assessments, and were randomized to receive either a 15‐min motivational or prescriptive interview". No further information given
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Cessation was verified through urinary cotinine levels.
Incomplete outcome data (attrition bias) All outcomes	Low risk	47/116 (41%) in the motivational arm and 61/114 (54%) in the prescriptive arm were lost to follow‐up at 6 months. Overall less than 50% loss to follow‐up ‐ similar rates between arms