Verbiest 2014.

Study characteristics
Methods	Design: Cluster‐randomized controlled trial Setting: General practices, The Netherlands Recruitment: Physicans were recruited by letter and a follow‐up telephone call. During the study period (January – August 2011), adult patients visiting participating GPs in both conditions were asked to complete a questionnaire after consultation
Participants	49 providers, 57.1% M, av. age 52 2068 patients at baseline, including 433 adults who smoked. No further demographic details specifically on those who smoked reported
Interventions	Intervention: general practitioners attended a single, 1‐hour training session based on the 5‐As behavior change model. In addition all general practitioners received a toolkit, which contained a smoking cessation care flowchart, a summary of pharmacological support, leaflets for patients, and an opportunity to receive additional feedback support Control: usual care defined as QUOTE: "the smoking cessation care that is usually provided by the general practitioner when not being trained, which is likely to vary between the general practitioners". No further details reported
Outcomes	Continuous abstinence at 9m Validation: None Measures of provider implementation: Ask, Advise, Assist–Prescribe, Arrange
Funding Source	Unrestricted grant from Pfizer and CAPHRI
Author's declarations of interest	Authored declared that they had no conflict of interest
Notes	Strategy: Provider Training + Flow sheet Level: Provider + Practice Type: Multicomponent vs. standard care
Risk of bias
Bias	Authors' judgement	Support for judgement
Sequence Generation	Low risk	QUOTE: "...using a simple randomization procedure (coin tossing) by an independent researcher not involved in the recruitment of the GPs"
Allocation concealment	Unclear risk	No details reported
Blinding of outcome assessors All outcomes	Low risk	Smoking status was self‐reported. At participant level, person‐to‐person contact did not differ
Incomplete outcome data All outcomes	Low risk	At participant level, including only those who reported smoking at baseline, the overall loss to follow‐up was 48.0% (n = 208/433); 42.6% (n = 83/195) in the intervention group and 52.5% (n = 125/238) in the control group at 9‐month follow‐up
Recruitment bias (cluster RCTs only)	Low risk	Participants were affiliated with the practices before randomization
Balanced baseline characteristics? (cluster RCTs only)	Low risk	QUOTE: "At baseline, more patients in the control group reported a chronic airway disease compared to the intervention group (15.4% vs. 12.4%; p=0.03)". Authors report using generalized estimating equations to adjust for participant characteristics
Adjustment for clustering in analysis? (cluster RCTs only)	Low risk	QUOTE: "Generalized estimating equations adjusted for clustering and patient characteristics"