Sinclair 1998.

Methods	Country: United Kingdom Design: Cluster‐randomised controlled trial of community pharmacies and pharmacy customers Study objective: To evaluate a training workshop for community pharmacy personnel to improve their counselling in smoking cessation based on the stage‐of‐change model Method of analysis: Multiple logistic regression Clustering adjustments made: "The estimates of intra‐cluster correlation (p) for the outcomes at each time point were calculated". The effects of clustering were negligible
Participants	Eligible for study: Pharmacies n = 76 (775 patients) Randomised: Pharmacies n = 62 (Patients: Intervention n = 224; Control n = 268) Completed: Pharmacies: Intervention n = 31; Control n = 29 (Patients: Intervention n = 159; Control n = 188) Age: Intervention 41.7; Control 41.5 Gender: Men n = 185; Women n = 302 Inclusion criteria: Pharmacy customers seeking advice on stopping smoking or buying an OTC anti‐smoking product in preparation for a new attempt to stop smoking; Recruitment period 12 months; No limit to number of recruits per pharmacy
Interventions	Setting: rural community pharmacies, Grampian, Scotland Intervention description: 2‐hour training workshop for pharmacists and pharmacy assistants: based on stages‐of‐change model and communication skills for negotiating change and providing ongoing support; no focus on smoking cessation products. Trained pharmacy staff offered participants the Pharmacy Support Programme which involved participant registration, counselling and ongoing record keeping at each subsequent purchase of OTC medications Control description: Usual care, mandated by UK law as a minimum of the display of health education material Duration of intervention: "Brief", exact time not specified
Outcomes	Prespecified outcomes: Self‐reported point prevalence of smoking at 1 month and continuous abstinence at 4 and 9 months; Age, gender, postcode (proxy for socioeconomic status), nicotine dependence (Fagerström test) recorded at 1 month post‐intervention; Consumer response to structured questionnaire assessing perception of the support package at 4 months Follow‐up period: 1, 4 and 9 months Self‐reported point prevalence at 1 month, continuous abstinence at 4 and 9 months
Notes	No additional pharmacy reimbursement. Evaluated effects of clustering by calculating ICCs for each outcome; concluded no evidence of significant cluster effect Funding: The Scottish Office, Department of Health Declarations of interest: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details of randomisation methods
Allocation concealment (selection bias)	Unclear risk	No information on allocation concealment methods
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: “Nine‐month smoking data were provided by a total of 73.2% (347) of the recruited customers: 73.3% (159) intervention and 73.2% (188) controls”
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Abstinence not biochemically validated Quote: “Intervention personnel offered their customers the Pharmacy Support Programme, which involved client registration, counselling, and record keeping. The control group asked customers to register and then continued to provide standard professional support.” Comment: Based on this description it is not clear if different amounts of face‐to‐face contact were provided
Selective reporting (reporting bias)	Unclear risk	No published protocol. All outcomes planned in the Methods section report on in the Results

CO: carbon monoxide; ICC: intra‐class correlation coefficient; ITT: intention‐to‐treat; MI: motivational interviewing; OTC: over the counter;