Buchsbaum 1993.

Methods	Cluster‐randomised trial
Participants	83 residents at the ambulatory medicine clinic of the Medical College of Virginia, Richmond (USA) and their 214 patients with harmful drinking habits
Interventions	A letter attached to the front of the patient's medical record with diagnostic information and treatment recommendations
Outcomes	Rates of physician counselling Assessed at: immediately after patient's session
Notes	1 relevant comparison (reminders versus control) Funding: This research was supported by a grant for Residency Training in General Internal Medicine, Bureau of Health Professions, Health Resources and Services Administration, Washington, DC, and by grant R01‐AA08278‐02, Improving Physician Management of Alcohol Disorders, National Institute of Alcohol Abuse and Alcoholism, Bethesda, Md
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	There is no mention of how the sequence was generated
Allocation concealment (selection bias)	Unclear risk	Not mentioned
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Participants were not blinded and it is not clear if patients were blinded
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No specific information about this
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss to follow‐up reported
Selective reporting (reporting bias)	Unclear risk	No specific information reported
Other bias	Low risk	None identified