Wednesday, September 18, 2013

Alcohol use - keeping an eye open

The complications of alcohol use are many. We are very good at listing the extensive number of possible problems that come along with alcohol use; nutritional deficiencies, myopathy, cognitive impairment, cirrhosis, cardiomyopathy, etc. however we are often fail to characterize the problem. Physicians underestimate the amount of alcohol ingested and when its identified, fail to capitalize on opportunities for rehabilitation. A US study found that only 48% of patients identified as having problem drinking were asked to follow-up, leaving the majority without ongoing monitoring. Patients may fail to have recognizable signs of cirrhosis despite significant liver injury, requiring probing questions to first identify the problem.


There are many tools for evaluating alcohol abuse. The most commonly used tool is the CAGE questionnaire. This method is great because of its simplicity and ease of administration, but fails to determine long term or changes in drinking patterns.It also lacks a quantitative component, which can be helpful to gauge severity of disease. A meta-analysis evaluating its use found the test to be more useful in inpatients compared to ambulatory assessment with a sensitivity of 87% and specificity of 90% for >2 components. Other tests do exist.

The alcohol use disorders identification test (AUDIT) is a longer test with higher sensitivity and specificity (96% and 97%). This was developed by the World Health Organization, and as a result was created for international use, validated in multiple languages. Of its 10 questions, it covers consumption, consequences and dependence issues, covering more areas than shorted questionnaires. Values of 8 and 20 are important to remember, being markers of harmful alcohol use and dependence.

Other markers of alcohol use which are mentioned on the wards and in the literature are macrocytosis and GGT levels. Unfortunately, these tests have limited sensitivity and specificity. A study in Hepatology from 1984 found GGT did offer some prognostic information in patients with acoholic cirrhosis, where only 60% of those with a level of 100 IU survived to 1 year.

An additionally proposed test for alcohol consumption is measurement of carbohydrate deficient transferrin. Transferrin circulates in our bodies in glycosylated forms. There is a variety of sugars attached to transferrin in different amounts. Alcohol consumption results in reduction of carbohydrate numbers on the transferrin molecule, something that can be detected in the blood. Studies have found that patients with low AUDIT scores are unlikely to have carbohydrate deficient transferrin. The test characteristics have been proposed to be better than that of GGT. I am not familiar with the cost of this assay and have never heard of anyone ordering this test.

All patients admitted with alcohol related complications, and more importantly those seen as outpatients with risk factors for alcohol abuse should be screened. Multiple methods exist, but when you have time the AUDIT form seems like an appropriate choice. See additional details below.

AUDIT score from BMJ best practices

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