THE VALUE OF LABORATORY TESTS FOR THE SCREENING AND RECOGNITION OF ALCOHOL-ABUSE IN PRIMARY-CARE PATIENTS

Background. Although alcohol abuse is prevalent in family practice, th e diagnosis is not easily established. Laboratory tests are usually he avily relied on in the diagnostic process. Methods. The value of labor atory tests for the screening and recognition of problem drinking in f amily practice is summarized, based on a review of the literature. A d istinction is made between studies in selected populations of drinkers and studies in nonselected populations, ie, family practice. Results. The most sensitive laboratory tests associated with excessive alcohol intake include gamma-glutamyl transferase (GGT), mean corpuscular vol ume, and the ratio of alanine aminotransferase to aspartate aminotrans ferase. No single laboratory test or combination of tests is shown to be appropriate for screening. The positive predictive value for GGT is only about 25% in a population that has a 10% prevalence of problem d rinking and increases to about 55% in a population that has a 30% prev alence of problem drinking. Conclusions. Guidelines for the recognitio n of problem drinking in family practice should include elevated labor atory test values as one of the ''alerting factors'' for problem drink ing, and not as a confirmation of a suspicion of problem drinking. In monitoring treatment response, GGT may be a powerful patient-motivatin g factor.