Aalto 2000.

Methods	Parallel group RCT: extended brief intervention versus brief intervention versus active control. ITT: outcome data were based on imputation of baseline values to participants lost to follow‐up.
Participants	Setting: Finland; primary care clinic. Participants 20 to 60 years, consuming ≥ 280 g absolute ethanol/week or CAGE ≥ 3 for men, ≥ 190 g absolute ethanol/week or CAGE ≥ 2 for women; excluded if severe psychiatric disease, or at least one detox treatment, or alcohol dependence, or alcohol‐related disease; screened by self‐administered health questionnaire including CAGE and quantity‐frequency consumption questions. Number randomised = 414; 71% male; mean age = 41.6 years; 18% comprehensive school, 7.3% vocational school, 12.7% college or university; 18.7% working/studying, 13.6% unemployed, 6% retired. At baseline: mean drinking amount per week = 286 g for men, 165.5 g for women, 259.8 g overall; mean drinking times per week = 2.2 for men, 2.1 for women; mean usual drinking amount per occasion = 139.2 g for men, 85.8 g for women; mean CAGE = 3.2 for men, 2.8 for women.
Interventions	Group A (N = 149) received brief intervention from GP or nurse at baseline, 2, 6, 12, 18, 24 and 30 months. Intervention was 10 to 20 minutes based on FRAMES according to the needs of individual participants. Group B (N= 137) received the same intervention less frequently: at baseline, 12 and 24 months. Group C (N = 128) received advice to reduce drinking and contact their GP in the event of health problems; were not told about 36 month follow‐up.
Outcomes	Mean drinking amount per week; drinking times per week; usual drinking amount per occasion; CDT, AST, ALT, GGT, MCV. Assessed at 36 months (blood tests additionally assessed at each brief intervention).
Funding source	Not reported.
Declaration of interests	Not reported.
Notes	Lahti project. Loss to follow‐up: Group A: 61/149 (41%). Group B: 55/137 (40%). Group C: 55/128 (43%).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Randomisation was performed by each participating general practitioner: before a participant arrived for a feedback session, the general practitioner drew a card from a mixed pack that included equal numbers of A, B, and C signs to refer the participant to the group which the participant was to be allocated" (p. 1682).
Allocation concealment (selection bias)	High risk	GP could see allocation and it was possible to subvert.
Blinding of treatment providers	High risk	GP provided intervention to all arms therefore risk of contamination between arms was high.
Blinding of participants	High risk	No reported attempt to blind participants.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Unclear whether outcome assessors were blinded.
Incomplete outcome data (attrition bias) All outcomes	High risk	Loss to follow‐up > 30%.
Selective reporting (reporting bias)	Unclear risk	Did not specify exact alcohol outcome measures in the methods.