Recent age-related domestic population demographics have shown significant growth in the elderly population, indicating that society is aging. In 2007, elderly people (aged ≥ 65) accounted for 9.9% of the total population in Korea, a 3.5% rise compared with 6.4% in 1997. Furthermore, the percentage of elderly individuals in Korea is expected to reach 14.3% in 2018, which is a definite sign of an aging population.¹⁾ The ever-growing aging population and the ensuing increase in elderly problem drinkers may lead to an increase in alcohol-induced physical, mental, and social problems.²⁾

Problem drinking is a comprehensive concept combining at-risk drinking and alcohol use disorders. Specifically, at-risk drinking in elderly males refers to heavy drinking, where a male consumes > 7 standard drinks of alcohol per week, and binge drinking, where a male consumes > 3 alcoholic drinks per drinking session.³⁾ Alcohol use disorders are defined as alcohol abuse or dependence according to psychiatric diagnostic criteria.⁴⁾ Problem drinking in elderly people raises mental and physical issues. Heavy drinking exacerbates diseases of the digestive system such as cirrhosis, liver cancer, oral cancer, esophageal cancer, and pancreatitis. It also elevates the morbidity rates of cardiovascular diseases, such as atrial fibrillation, hypertension, and stroke, and mental diseases, such as alcohol dependence, depression, anxiety disorders, and suicidal ideation.^5,6)

Thus, to solve alcohol-related problems in elderly drinkers, clinicians need to identify problem drinking at its early stages. In clinical settings, however, few cases of alcohol-related problems in elderly drinkers are identified. A study at a university hospital in the Netherlands found that only 33% of elderly alcohol abuse patients were identified by clinicians.⁷⁾ Likewise, a three-hospital study in Australia reported that just 33% of these patients were discovered by clinical professionals.⁸⁾ The percentages are remarkably lower compared with the discovery rate (60%) of alcoholism in patients below 60 years of age. In short, 2/3 of elderly drinking problems are not discovered by clinicians.

Such low discovery rates may be due to several factors. First, elderly patients are more vulnerable to alcohol than are younger patients. That is, even when elderly people consume the same amount of alcohol as younger people do, their blood alcohol concentration is higher. Therefore, moderate drinking in young people may constitute heavy drinking in elderly people. This fact is often overlooked. Second, although 90% of elderly individuals with alcohol use disorders are treated for their physical problems, clinicians tend not to pay att ention to drinking problems, which are non-specific and hard to identify.⁹⁾ Third, negative attitudes toward alcoholism get in the way of making an accurate diagnoses. The stigma of alcoholism often leads alcoholics to drink in solitude, thereby missing the chance to be seen by clinicians at the appropriate time.¹⁰⁾

Evaluating the validity of screening tools used for the assessment of problem drinking in the elderly population is very important in terms of patient care in primary medical care settings. It is most desirable to diagnose at-risk drinking or alcohol use disorders through face-to-face interviews conducted by doctors. When such interviews are impossible, screening questionnaires completed by patients play an important role. Doctors may review the results of screening tests, suspect at-risk drinking or alcohol use disorders, and conduct further interviews for confirmation. Previous Korean studies based on the utility of alcohol questionnaires have focused largely on younger and older adults. Few studies have examined whether the screening tools are suitable for assessing drinking problems in the elderly. Accordingly, the present study attempted to assess the validity of three screening tools commonly used in primary care sett ings to identify problem drinking (at-risk drinking and alcohol use disorders) in elderly male drinkers.

It is important to identify patients with alcoholism in primary care settings so that they can receive proper treatment. However, it would be better to screen problem-drinking patients at earlier stages to foster prevention. As at-risk drinking in the form of continuous drinking rather than developed alcoholism is often found in elderly people, screening tools that effectively identify drinking problems are required.¹⁷⁾ The present study chose the AUDIT, CAGE, and SMAST-G questionnaires as screening tools for at-risk drinking and alcohol use disorders and investigated each tool's AUROC and optimal cut-off score.

In the present study, the AUDIT showed the greatest AUROC value in screening for at-risk drinking in the elderly. This may be attributed to the fact that, in contrast to the SMAST-G and CAGE questionnaires, the AUDIT contains items assessing the frequency of drinking and the amount of alcohol consumed as a means of assessing heavy drinking or binge drinking. Based on the results of this study, the cut-off score for the AUDIT for screening at-risk drinking in males aged ≥ 65 years, was 7 points and higher. This score differs from 12 points, the cut-off point identified by Kim et al.¹²⁾ and presented in their study on adult Korean males. The difference in cut-off scores likely reflects the drinking habits of elderly problem drinkers, who tend to consume a certain amount of alcohol on a continuing basis rather than engaging in occasional binge drinking.¹⁷⁾ Additionally, the difference in cut-off scores may have been resulted from the modified AUDIT questions used in the current study. More specifically, due to the changes in the concentration of Soju, consuming a bottle of Soju was scored as 3 points (7 standard drinks) for AUDIT question number 2 in the previous study, whereas it was scored as 1 point (4 standard drinks) in the current study. Similarly, consuming a bottle of Soju (7 units in Soju cups) was considered to be binge drinking on question number 3 in the previous study but not in the current study, resulting in an overall decrease in respondents' drinking scores. Also, regarding the cut-off score of the AUDIT in screening for alcohol use disorders, the present study found 11 points to be an optimal cut-off score in elderly men. This was lower than the score of 15 points presented in the previous study¹²⁾ based on adult males of all ages. This may be attributable to the same phenomenon as the cut-off score in screening for at-risk drinking. In short, it seems necessary to set lower cut-off scores on the AUDIT in elderly men than those used for the general adult male population.

The validity of the SMAST-G questionnaire has never been studied in Korea to the best of our knowledge. Regarding screening for alcohol use disorders in elderly men, the results of the present study fit well with those of the earlier study by Morton et al.,¹⁸⁾ which reported that the SMAST-G exhibited 69.8% sensitivity, 80.5% specificity, and an AUROC of 0.84 based on 120 veterans aged ≥ 65 years. However, Morton et al.¹⁸⁾ concluded that the SMAST-G was the best tool among the AUDIT, CAGE, and SMAST-G, based on their subjects. The present study, in contrast, found that the AUDIT was more useful than the SMAST-G. This difference may be partly due to items included in the DSM-IV criteria for alcohol abuse, such as repeated problems in social relationships and legal issues, which were not stressed in the DSM-III criteria. The cut-off score of 2 points for the SMAST-G for use in screening for at-risk drinking in elderly men in the current study is consistent with cut-off scores reported previously.^15,19) Also, 4 points, identified as the optimal cut-off score for use in screening for alcohol use disorders in our study, is thought to be similar to 5 points presented by previous studies.^20-22)

The CAGE questionnaire has a small number of items and is simple and easy to use in outpatient settings, although it proved less applicable to the elderly population in the current study. In this study, the CAGE questionnaire was found to have 60% sensitivity and 68% specificity in screening for at-risk drinking and 87% sensitivity and 63% specificity in screening for alcohol use disorders in this elderly population. A previous domestic study by Park et al.¹⁴⁾ on the validity of the CAGE in adult male drinkers found 76.1% sensitivity and 90.0% specificity in screening for alcohol use disorders. Compared with the previous study, the sensitivity was higher and the specificity was lower in the present study, which seems attributable to demographic differences in the subjects. In the study by Park et al.,¹⁴⁾ subjects aged ≥ 60 years accounted for 5% of the entire sample, whereas the present study dealt entirely with men aged ≥ 65 years only. The cut-off score of 2 points for the CAGE questionnaire in the current study as the reference score in screening for alcohol use disorders in elderly men fits well with the cut-off score suggested by Park et al.;¹⁴⁾ however, this score is 1 point higher than that presented by Jones et al.²³⁾ This seems partly attributable to the fact that people in the East tend to hold more liberal viewpoints on drinking, especially drinking by elderly people, than do those in the West.

Some limitations of the present study should be addressed. First, the authors' efforts to include drinkers as subjects may have resulted in a bias toward heavy and binge drinkers. This may have led to the improper representation of general socio-demographic characteristics. Second, eight subjects (3.3%) were patients with alcohol abuse, and 38 subjects (15.7%) had alcohol dependence. Thus, fewer subjects abused alcohol than were alcohol dependent. In interpreting the results, it should be noted that the DSM-IVTR criteria for alcohol abuse that emphasizes "drinking even in cases of role-fulfillment disorder including absence and failure in duty and in physically dangerous situations such as drunken driving and operating machines" may not be applicable to elderly people, who are socially and occupationally less interactive. The fact that the subjects were elderly people (71.8 years old mean age) and 77.7% of the subjects were unemployed in this study also supports the above-mentioned points.

In conclusion, the present study investigated the utility of three alcohol-screening tools, the AUDIT, SMAST-G, and CAGE questionnaires, in screening for drinking problems in elderly men and found that the AUDIT proved the most useful in screening for at-risk drinking and alcohol-use disorders in elderly Korean men.