Romelsjö 1989.

Methods	Parallel RCT: brief intervention versus brief advice. ITT: unclear.
Participants	Setting: Sweden, primary care district health centres. Participants: 18 to 64 years, consuming at least 40 g 100% ethanol per day for men and 30 g for women, or drinking in the morning at least every second time when drinking alcohol, or having difficulties restricting drinking at least every second time when drinking alcohol, or CAGE ≥ 3, or elevation of GGT; screened by mailed general health questionnaire incorporating alcohol consumption questions and CAGE, and a telephone interview followed by a health examination; excluded if inpatient care for alcoholism or alcohol psychosis in previous three years, or care at an inebriate's institution in previous three years, or other substance abuse in previous three years, or ongoing treatment or need for treatment for a mental disorder, or severe somatic disease, or other potential causes of elevated GGT. Number randomised = 83; 84% male; mean age = 46.3 years (range = 21 to 64 years); 86% employed. At baseline: GGT = 2.0 Ukat/l; daily alcohol consumption = 29.1 g 100% ethanol; 'problems index' = 11.3.
Interventions	Intervention group (N = 41) were advised by their GP to cut down their alcohol consumption by the next visit, and if this seemed difficult, to abstain from alcohol. Elevated GGT values and changes in GGT over time were used in discussion with patients in a biofeedback approach. Patients were asked to visit the laboratory again so that the new GGT values were at the GP’s disposal at the visit. The GP treated other conditions when necessary, and tried to get a good picture of the patient’s social and psychological condition and to give support. The time interval between visits was according to the GP’s judgement. The mean number of visits to the GP was about three. Control group (N = 42) were told by their general practitioner that they should cut down on alcohol consumption and that a follow‐up examination was planned for approximately one year later. They had earlier been informed by the nurse that their alcohol consumption was elevated or, by letter, that their GGT was elevated.
Outcomes	Change in GGT; change in self‐reported alcohol consumption; change in a combined measure of alcohol problems 'problem index'. Assessed at one year.
Funding source	This work was supported by a grant from the Swedish Ministry of Health and Social Affairs, the Commission for Social Research (Project No D84/212:1) and by the Stockholm County Council.
Declaration of interests	Not reported.
Notes	Loss to follow‐up: Intervention group = 5/41 (12%). Control group = 6/42 (14%).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomisation was performed by the project leader according to a randomisation scheme unknown to the GPs; each patient was randomised to reach an equal number of patients from each group per GP... distribution for all GPs was considered... then the total distribution was considered... if this distribution was equal, ultimately the choice was made by coin flipping" (p. 1320).
Allocation concealment (selection bias)	Low risk	Allocation sent in a closed envelope to the GP, which was opened only after the first visit. The rationale for this, which worked well, was that the attitude or behaviour of the GP towards the patient should not be affected by knowledge of allocation (p. 1320).
Blinding of treatment providers	High risk	Not blinded.
Blinding of participants	Low risk	It was attempted to conduct the interviews as a rather open talk on health and social questions; alcohol questions were embedded in other health‐related questions (p. 1320).
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessment was carried out in a lab.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Loss to follow‐up reported but only reasons are "drop‐out".
Selective reporting (reporting bias)	Low risk	Outcomes specified in methods are reported.