Canga 2000.

Methods	‐ Randomised controlled trial ‐ Randomisation and concealment of allocation: adequate ‐ Adequate blinding of patients, administrators and outcome assessors ‐ description of losses to follow‐up and intention‐to‐treat analysis ‐ Groups similar at the start of the study ‐ Groups equally provided of care ‐ Overall judgement of quality: good
Participants	‐ 280 type 2 diabetes patients in outpatient settings in an urban area in Spain ‐ Multicentre study ‐ Sex: intervention (F: 22, M: 125), control (F: 18, M: 115) ‐ Age: intervention (54.4 +‐ 15), control (55.8 +‐ 14.9) ‐ Daily cigarettes: intervention (19.9 +‐ 11.9), control (19.8 +‐ 11.5) ‐ Years of smoking: intervention (36.4 +‐ 16), control (38 +‐ 15.2) ‐ BMI: intervention (27.0 +‐ 4.7), control (26.2 +‐ 4.4) ‐ treatment modality: insulin (intervention 47, control 47)
Interventions	Nurse‐led education and counseling versus usual care for smoking cessation.
Outcomes	Self‐reported and verified smoking cessation. Change in mean cigarettes per day.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk