Sawicki 1993.

Methods	Study design: Randomized controlled trial Country: Germany Recruitment: From a university diabetic outpatients clinic
Participants	Diabetic smokers prepared to participate in a stop‐smoking programme; 40% women, av. age 37, av. cpd 21
Interventions	1. Extensive behaviour therapy including self‐control. 10 x 90‐min weekly sessions. Led by a psychotherapist 2. Physician advice, 15‐min unstructured session. NRT offered in the case of severe addiction
Outcomes	Abstinence at 6 m Validation: serum cotinine < 20 ng/ml
Notes	Comparison 1.3.1
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomized, method not described
Allocation concealment (selection bias)	Unclear risk	No details given
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Biochemical validation of abstinence
Incomplete outcome data (attrition bias) All outcomes	Low risk	25/44 participated in group programme and 31/45 received physician advice Non‐participants followed up and included in ITT analysis