The relative value of consultation, questionnaires and laboratory investigation in the identification of excessive alcohol consumption.

Alcohol is a major cause of morbidity and mortality in Britain. Consultation, questionnaires and laboratory tests may all be used to help identify alcohol abuse and thereby prevent and treat alcohol-related problems. Consultation which can identify 80% of alcohol abusers involves recording the findings of alcohol and general histories and physical examination. The accuracy of the assessment depends on the reliability of the respondent and the respondent's relations and friends, and on the skill of the investigator; however, thorough assessment is time-consuming and expensive. Questionnaires may identify up to 80% of alcoholics. They are generally based on the Michigan Alcohol Screening Test and CAGE questionnaires and are simple, rapid to complete, inexpensive and not dependent on skilled investigators; however, the principal disadvantage of using questionnaires is that a personal relationship is not developed with the subject. Finally, simple and complex laboratory tests may be used. Of the simple laboratory tests, raised GGT or MCV levels are the most useful and when these values are combined, 90% of alcoholics may be identified correctly. Complex laboratory tests may exhibit greater sensitivity and specificity and provide useful additional information; however, their restricted availability limits their widespread use. The value of each of these methods depends on the objective of the assessment. For population surveys, questionnaires are of greatest relative value and consultation and laboratory tests may be used to confirm the presence of alcohol abuse. In general practice and the hospital setting, it is imperative to include questions on alcohol intake and alcohol-related problems in all interviews with patients. Laboratory tests may be used to confirm suspected alcohol abuse and questionnaires may provide useful screening tools. Finally, in the specialist alcohol unit, consultation, questionnaires and laboratory investigations are all important for identifying alcohol abuse. In this setting, consultation is of particular importance and the alcohol history and physical examination should be recorded by a skilled investigator and the results confirmed with relatives and close friends. Questionnaires are useful as initial screening or assessment tools and computer-based systems may facilitate data collection. Simple and complex laboratory tests may be used to confirm the diagnosis and help ascertain the extent of disease. By assuming that 'all patients have alcohol-related problems until proven otherwise', and through the appropriate application of consultation, questionnaires and laboratory tests, identification of excessive alcohol consumption and the prevention of its sequelae will be facilitated.