Each participating clinic serves as its own control and as control for active clinics, in the stepped-wedge design. All clinics are inactive (no intervention) during the baseline period of three months.

Active clinics are trained in the intervention object (the 15-method) prior to switching to the active group. Clinics are enrolled as active clinics (intervention) in four steps (4-5 clinics in each step). The intervention is implemented into the clinic, and the staff are free to use the intervention in everyday work.

The 15-Method is a Screening and Brief Intervention method for identifying and treating alcohol problems in primary care. The method combines evidence-based approaches from specialized addiction treatment with screening and readily available treatment options in general practice to help identify and treat alcohol problems. The 15-method is based on Motivational Interviewing, Cognitive Behavioral Therapy and utilizes the Alcohol Use Disorder Identification Test (AUDIT) as a screening tool. The 15-Method contains three flexible steps: Identification of clinical problem related to alcohol; feedback and clinical work-up as needed; treatment. Treatment includes structured consultations (maximum of four) with patient home-work assignments, and can be combined with pharmacological treatment for alcohol problems.

Using Timeline Follow Back one-week data from patient surveys. The Danish national low-risk alcohol consumption limit is maximum 10 standard units (1 unit = 12 grams of ethanol) per week and maximum 4 standard units on a single day. Patients are coded 1 (drinking above limits) or 0 (not drinking above limits).

The number of heavy drinking days (HDD) per week is derived from the Timeline Follow Back one-week (range 0-7 HDD/week) in patient surveys. A HDD is defined as >4 standard units (1 unit = 12 grams of ethanol) on the same day. Is a sum of the number of days patients drink >4 standard units.

The likelihood of consultations in which the topic of alcohol has been addressed. Alcohol related consultations are continuously registered in the patient filing system throughout the trial period. An alcohol related consultation is defined as a consultation registered with the ICD-10 code z006 and ICPC-2 code A97.