Hilberink 2011.

Study characteristics
Methods	Design: 3‐group cluster‐randomized controlled trial Setting: Primary care, The Netherlands Recruitment: Patients with COPD identified from medical records in participating practices
Participants	667 patients with COPD (148 control, 243 intervention 1, 276 intervention 2), age > 35 years, av.age 60, 16 cpd, 49% M
Interventions	Intervention 1: counseling strategy, recommendation of NRT • The general practice team received a 4‐hour group training session about chronic obstructive pulmonary disease and smoking cessation, and 3 visits by an outreach visitor for additional individual support • Participants received a leaflet especially developed for people with chronic obstructive pulmonary disease who smoked, a videotape, self‐efficacy enhancing information, information about NRT, proactive telephone calls Intervention 2: counseling strategy, recommendation of NRT, advice to use bupropion‐SR • The general practice team received a 4‐hour group training session about chronic obstructive pulmonary disease and smoking cessation, and 3 visits by an outreach visitor for additional individual support • Participants received a leaflet especially developed for people with chronic obstructive pulmonary disease who smoked, a videotape, self‐efficacy enhancing information, information about NRT, proactive telephone call, and advice to use bupropion‐SR Control: usual care consisting of periodic regular check‐ups and chronic obstructive pulmonary disease information
Outcomes	PPA at 12m Validation: Urinary cotinine < 50 ng/mL
Funding Source	Financed by the Dutch Asthma Foundation, Netherlands Organization for Health Research and Development (ZonMW), and Pharmacia
Author's declarations of interest	Authors declared that they had no conflict of interest
Notes	Strategy: Provider training, outreach facilitation, adjunctive counseling Level: Patient + Provider + Practice Comparison type: Multicomponent vs. SC
Risk of bias
Bias	Authors' judgement	Support for judgement
Sequence Generation	Unclear risk	No details reported
Allocation concealment	Unclear risk	No details reported
Blinding of outcome assessors All outcomes	Low risk	Smoking status was biochemically validated
Incomplete outcome data All outcomes	Low risk	Attrition rates were under 50% and similar between groups. The overall loss to follow‐up was 18.7% (n = 130/697); 3.6% (n = 9/252) in 'counseling + NRT' group, 5.2% (n = 15/291) in 'counseling+NRT+prescription of bupropion' group, 3.9% (n = 6/154) in the control group were lost to follow‐up at 1 year.
Recruitment bias (cluster RCTs only)	Low risk	Participants were affiliated with the practice before randomization.
Balanced baseline characteristics? (cluster RCTs only)	Low risk	Groups were balanced
Adjustment for clustering in analysis? (cluster RCTs only)	Low risk	QUOTE: "We used multilevel analyses to test treatment effects because of the study's hierarchical structure..."