1 Center for Drug and Alcohol Programs, Medical University of South Carolina, Charleston, 2 Department of Family Medicine, Medical University of South Carolina, Charleston and 3 Department of Medicine and Center for Health Care Research, Medical University of South Carolina, Charleston, SC 29425, USA
* Author to whom correspondence should be addressed at: Center for Drug and Alcohol Programs, Medical University of South Carolina, 67 President Street, P.O. Box 250861, Charleston, SC 29425, USA. E-mail: millerpm{at}musc.edu
(Received 20 December 2003; first review notified 6 March 2004; in revised form 2 April 2004; accepted 5 April 2004)
![]() |
ABSTRACT |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
![]() |
INTRODUCTION |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
In spite of these recommendations as well as the availability of valid and reliable screening tools, only 5565% of physicians routinely ask patients about alcohol use on the initial visit and only 35% screen patients during annual visits (Bradley et al., 1995; Spandorfer et al., 1999
). Physicians are most likely to know about and use quantity/frequency questions to screen (Bradley et al., 1995
). A survey of a university-based department of medicine found that only 45% of the physicians had heard of the CAGE screening questions and only 14% could list all four questions (Ford et al., 1994
).
Together with self-report alcohol screening tools, biochemical measures of alcohol consumption provide an accurate and reliable way to assess heavy drinking in patients. While mean corpuscular volume (MCV) is used for alcohol screening, gamma-glutamyltransferase (GGT) is the most commonly used biomarker of heavy drinking (Allen and Litten, 2001). Chronic drinking of four or more drinks per day for 48 weeks may significantly raise levels of this blood protein in a number of individuals. However, nonalcoholic liver disease can also increase GGT levels, increasing the likelihood of false-positive results.
Carbohydrate-deficient transferrin (CDT) is a newer biomarker that is equally or more clinically sensitive than GGT but generally more specific (Anton et al., 2002). Few medical conditions (i.e. end stage liver disease, biliary cirrhosis, and rare genetic variability) other than heavy drinking will elevate CDT levels. Of interest is the lack of a significant relationship between CDT and GGT, each being an independent marker of excessive alcohol use (Anton et al., 2002
).
While knowledge and use of quantity/frequency and CAGE questions have been investigated, studies of primary care screening with alcohol biomarkers have not been reported. The present investigation sought to identify knowledge and practices of a select group of primary care physicians regarding eliciting patients' self-reports and ordering biomarker alcohol screening.
![]() |
METHODS |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Our survey was conducted at the annual meeting of members in July of 2003. Twenty-two practices were represented by one or more physicians as well as mid-level providers, nurses and administrative personnel. Although all physicians in attendance were affiliated with PPRNet and, in most cases, had been exposed to training in evidence-based clinical guidelines, none had received any special training in alcohol screening guidelines through PPRNet. In addition, this was a general annual meeting that was not related to alcohol.
Instruments
The Clinical Practice Survey, a ten-item questionnaire about alcohol screening designed specifically for this project, was administered to physicians in attendance. The survey was completed anonymously and consisted of demographic data on age, gender, medical specialty (e.g. family practice, internal medicine, etc.), years in practice, and approximate number of patients seen per week. Questions were included regarding familiarity with and use of quantity/frequency questions, the CAGE questions, the Alcohol Use Disorders Identification Test (AUDIT), mean corpuscular volume (MCV), gamma-glutamyltransferase (GGT), and carbohydrate-deficient transferrin (CDT).
Questions about familiarity were rated on a 5-point Likert scale from Very Unfamiliar to Very Familiar. Questions regarding frequency of use were rated on a 5-point Likert scale including the categories of Never, Occasionally, Frequently, Almost Always, and Always. Questions also included reasons for not ordering an alcohol biomarker lab test including Don't have the time, Tests are not specific enough, Concerns about false positives, Too costly, Providers do not cover costs, Unfamiliar with their use, Unfamiliar with their interpretation, Patients might object, Questionnaires are sufficient, Not my responsibility to screen, and Other. These reasons were rated on a 5-point Likert scale from Totally Unimportant to Extremely Important. Finally, a question about factors that would influence a decision to use biomarkers more often was asked.
Two summary scores were created for familiarity with and frequency of use of alcohol biomarkers, each of which was created by averaging the three questions corresponding to familiarity with and frequency of use of MVC, GGT and CDT. Two separate multivariate linear regression models were used to assess whether physician age, gender, years in practice, or approximate number of patients seen per week was significantly and independently associated with each of the two biomarker summary scores. All analyses were performed using SAS® (Cary, NC).
![]() |
RESULTS |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Table 1 lists the distribution of the responses to the individual questions as well as the average scores.
|
The mean rating for familiarity with biomarker screening tools was 3.4 (s.d. = 0.7), on a 1 to 5 scale (with 5 being very familiar), indicating that respondents were almost as familiar with alcohol biomarker screening as they were with non-biomarker screening. However, physicians were much more familiar with MCV and GGT than CDT. While 85% marked the two highest categories of familiarity with regard to MCV and GGT, only 8.4% were that familiar with CDT.
The mean rating for use of biomarker lab tests was 2.0 (s.d. = 0.6), indicating only occasional use in practice. As with the familiarity data, there was a marked discrepancy between use of MCV and GGT compared to CDT. A total of 54.2% use MCV Frequently, Almost always or Always, with 35% using GGT that often. Only 6.3% order CDT lab tests that often, with 93.8% never ordering CDT.
Results from a multivariate regression model suggest that familiarity with alcohol biomarkers was significantly (P = 0.038) greater among male physicians than females and significantly (P = 0.022) greater among internal medicine physicians compared with family practice physicians and specialists. Physician age, number of years in practice, and average number of patients per week were all not significantly associated with familiarity with alcohol biomarkers. A second regression model indicated that none of the physician characteristics of interest were significantly (P > 0.05) associated with frequency of use of alcohol biomarkers.
Reluctance to order biomarker tests was most related to unfamiliarity with their use and interpretation, a feeling that questionnaires are sufficient for alcohol screening, and a concern that providers do not cover costs for such tests (in fact, in the United States, Medicare and Medicaid pay for this test and health insurance providers will pay within the limits of the policy). Fully 95.8% would consider using CDT more often if they had more knowledge about it. Proof of the sensitivity and specificity of CDT together with evidence of a strong association between CDT and specific health risks (e.g. hypertension) would encourage almost 90% of these physicians to use this biomarker more frequently.
![]() |
DISCUSSION |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Interestingly, only a small minority of physicians had knowledge of the AUDIT questionnaire. This is noteworthy since the AUDIT, developed by the World Health Organization (WHO) specifically for primary care settings, is a well-validated screening tool with generally better sensitivity and specificity than the CAGE (Saunders et al., 1993). However, these results are not surprising since the latest NIAAA published screening guidelines for physicians do not describe or recommend use of the AUDIT (NIAAA, 2003
).
Compared to questionnaires, few physicians use alcohol biomarker screening on a regular basis. Interestingly, MCV, the alcohol biomarker test most widely used by this group, has been shown to be of limited value in general medical practice because of its low sensitivity and predictive value (Conigrave, 1995). CDT, especially in combination with GGT, is used little, if at all, by this group, even though it is a highly sensitive and specific instrument for use in assessing alcohol consumption in general medical practice patients (Meerkerk et al., 1998
).
It is apparent but not surprising that this group of physicians was unfamiliar with alcohol biomarkers. First, NIAAA guidelines (written before availability of CDT in the United States) discourage the use of biomarkers for screening in primary care and recommend them for monitoring purposes only. Second, studies on biomarkers are typically published in specialized alcohol research journals, not usually read by clinicians. Third CDT, the least-known biomarker in this study, was only approved by the FDA for clinical use in 2001 and its assay is not as yet widely available in the United States.
Use of biomarkers was not related to any specific characteristics of the physician or his/her practice. It would be important to survey a wider and perhaps younger selection of physicians to determine if age or years since leaving training are relevant. In fact, a limitation of the present study is the fact that we surveyed only a small, select sample of primary care physicians.
Finally, it is interesting to note that these physicians reported that they would consider more frequent use of alcohol biomarkers if they knew more about their use, interpretation, specificity, sensitivity and association with specific medical conditions. In fact, biomarkers such as CDT have shown detection sensitivity of 0.73 and specificity of 0.96 with general medical patients (Meerkerk et al., 1998). In addition, recent studies have found that elevated GGT is positively associated with hypertension (Hashimoto et al., 2001
; Lee et al., 2001
) and that % CDT levels are useful in detecting and/or confirming high-risk drinking in patients being treated for Type 2 diabetes and hypertension (Fleming and Mundt, 2004
).
It is apparent that state-of-the-art research on alcohol screening has not been translated into national guidelines or to real-world medical practices. The need for increased technology transfer efforts in this regard is apparent.
![]() |
ACKNOWLEDGEMENTS |
---|
![]() |
REFERENCES |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Anton, R. F., Lieber, C. and Tabakoff, B. (2002) Carbohydrate-deficient transferrin and gamma-glutamyltransferase for the detection and monitoring of alcohol use: Results from a multisite study. Alcoholism: Clinical and Experimental Research 26, 12151222.[ISI][Medline]
Bendtsen, P. and Akerlind, I. (1999) Changes in attitudes and practices in primary health care with regard to early intervention for problem drinkers. Alcohol and Alcoholism 34, 795800.
Bradley, K. A., Curry, S. J., Koepsell, T. D. and Larson, E. B. (1995) Primary and secondary prevention of alcohol problems: U.S. internist attitudes and practices. Journal of General Internal Medicine 10, 6772.[ISI][Medline]
Conigrave, K. M., Saunders, J. B. and Whitfield, J. B. (1995) Diagnostic tests for alcohol consumption. Alcohol and Alcoholism 30, 1326.[Abstract]
Fleming, M. F. (2002) Screening, assessment and intervention for substance use disorders in general health care settings. In Strategic Plan for Interdisciplinary Faculty Development: Arming the Nation's Health Professional Workforce for a New Approach to Substance Use Disorders, Haack, M. R. and Adger, H. eds, pp. 4666. Association for Medical Education and Research in Substance Abuse (AMERSA), Providence, RI.
Fleming, M. F. and Mundt, M. (2004) Carbohydrate Deficient Transferrin: Validity of a New Biomarker in a Sample of Diabetic and Hypertensive Patients. Journal of the American Board of Family Practice. In press.
Ford, D. E., Klag, M. J., Whelton, P. K., Goldsmith, M. and Levine, D. (1994) Physician knowledge of the CAGE alcohol screening questions and its impact on practice. Alcohol and Alcoholism 29, 329336.[Abstract]
Hashimoto, Y., Futamura, A., Nakarai, H. and Nakahara, K. (2001) Relationship between response of gamma-glutamyl transpeptidase to alcohol drinking and risk factors for coronary heart disease. Atherosclerosis 158, 465470.[CrossRef][ISI][Medline]
Lee, D. T., Ha, M., Kim, J., Gross, M. and Jacobs, D. (2001) Gamma-glutamyltransferase, alcohol, and blood pressure: A four-year follow-up study. AEP: Association of Educational Psychologists Journal 12, 9096.
Meerkerk, G. J., Njoo, K. H., Bongers, I. M., Trienekens, P. and van Oers, J. A. (1998) The specificity of the CDT assay in general practice: the influence of common chronic diseases and medication on the serum CDT concentration. Alcoholism: Clinical and Experimental Research 22, 908913.[ISI][Medline]
National Institute on Alcohol Abuse and Alcoholism (2003) Helping Patients with Alcohol Problems (Vol. NIH Publication No. 03-3769). National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD.
Ornstein, S. M., Hanson, R. M., Corley, S. T. and Jenkins, R. G. (2001) High performance of clinical preventive services: Approaches of best practices. Preventive Medicine in Managed Care 2, 7984.
Saunders, J. B., Aasland, O. G., Babor, T. F., de la Fuente, J. R. and Grant, M. (1993) Development of the Alcohol Use Disorders Identification Test (AUDIT): WHO Collaborative Project on Early Detection of Persons with Harmful Alcohol ConsumptionII. Addiction 88, 791804.[ISI][Medline]
Spandorfer, J. M., Israel, Y. and Turner, B. J. (1999) Primary care physicians' views on screening and management of alcohol abuse: Inconsistencies with national guidelines. Journal of Family Practice 48, 899902.[ISI][Medline]
Wallace, P. and Haines, A. (1985) Use of a questionnaire in general practice to increase the recognition of patients with excessive alcohol consumption. British Medical Journal 290, 19491953.[ISI][Medline]