Text adapted in 2022 from The Primary Care Addiction Toolkit (online only). A complete list of Toolkit authors, editors and contributors is available here.
Screening for Harmful Alcohol Use: The Basics
The following four steps can assist clinicians in better detecting unhealthy alcohol use:
- Take an alcohol use history: Incorporate questions about alcohol use into routine lifestyle questions for all patients.
- Use a screening tool: Use the AUDIT-C, AUDIT-10 (manual and questionnaire), or other validated screening questionnaire for all patients who drink alcohol.
- Order lab tests: Request appropriate laboratory tests if alcohol use is suspected to be a problem.
- Investigate alcohol as possible cause of other health issues: Determine whether alcohol is contributing to other health issues a patient is experiencing.
Take an alcohol use history
Incorporate questions about alcohol use into routine lifestyle questions for all patients.
Ask patients about their typical weekly consumption and maximum daily consumption:
- "On average, how many days per week do you drink alcohol?"
- "On a typical day when you drink, how many drinks do you have?"
- "What is the maximum number of drinks you have had on any one day during the past three months?"
Convert responses to standard drinks.
If patients give vague responses or you think they may be under-reporting their consumption, try these strategies:
- Ask about alcohol consumption in the past week or the past day.
- Ask about the number and size of bottles purchased per week.
- Present patients with a wide range of consumption.
- Let patients know that you won't be shocked by heavy consumption: "Would you say you drink one or two beers per night, or 10 or 12 beers per night?"
- Provide a medical or social excuse for drinking: "Many people have a drink or two to help them get to sleep. Do you ever have a drink before bed?"
- "Do you ever have a glass of wine with dinner? How about at Christmas or New Years?"
Document current alcohol use on every patient's chart, including:
- The number of drinks per week.
- The maximum drinks on any day in the past three months.
Use a screening tool
AUDIT-C
The three-question AUDIT-C is simple to administer, but is prone to generating false positives. As with other screening tests, patients who screen positive should be fully assessed before an alcohol use disorder is diagnosed.
AUDIT-10
The AUDIT-10 (manual and questionnaire) is longer than the AUDIT-C, but has excellent sensitivity and specificity. A cut-off score of 8 or more indicates unhealthy drinking. Newer research suggests that the cut-off be lower for women (Johnson et al., 2007; Levola & Aalto, 2015; Neumann et al., 2004).
The CAGE questionnaire
The four-item CAGE is easy to memorize and identifies most patients with an alcohol use disorder (Dhalla & Kopec, 2007).
Order lab tests
Blood tests can help to identify excessive alcohol use and possible liver damage. These tests have a low sensitivity and therefore should be used only to confirm suspected alcohol problems, not as a sole screening test.
Blood tests can also be used to monitor changes in patients' alcohol consumption. Informing patients of their test results gives them concrete evidence of their progress.
Gamma glutamyl transferase (GGT)
An elevated gamma glutamyl transferase (GGT) level may indicate high alcohol consumption. The GGT test is not specific to alcohol, however, and can be increased in people with non-alcoholic liver disease, diabetes or obesity, and who use certain medications (e.g., phenytoin). GGT has a half-life of two to four weeks, so if GGT is elevated because of drinking, the level will decrease by half after two to four weeks of abstinence.
Complete blood count (CBC)
Mean cell volume (MCV), an index of red blood cell size, increases with heavy drinking. This test is less sensitive than GGT. MCV is also elevated in people with folate or vitamin B12 deficiency, non-alcoholic liver disease or hypothyroidism, and who take certain medications (e.g., phenytoin).
MCV's half-life is three months, so if MCV is elevated because of drinking, the level will decrease by half after three months of abstinence.
Investigate alcohol as possible cause of other health issues
Patients with the following symptoms should be screened for alcohol problems:
- Musculoskeletal symptoms: trauma
- Gastrointestinal symptoms: gastritis, esophagitis, fatty liver, elevated transaminases
- Cardiovascular symptoms: hypertension
- Psychiatric symptoms: depression, anxiety, insomnia, social and family dysfunction
Be aware that patients tend not to count heavy drinking episodes in their estimate of average weekly consumption.