Journal Club Alcohol and Health: Current Evidence November-December 2005

Featured Article Combining the AUDIT questionnaire and biochemical markers to assess alcohol use and risk of alcohol withdrawal in medical inpatients Dolman JM, et al. Alcohol Alcohol. 2005;40(6):515–519.

Study Objective To examine whether the AUDIT* and/or blood testing could… predict risk of alcohol withdrawal in medical inpatients *Alcohol Use Disorders Identification Test

Study Design Screening with the AUDIT and blood testing (GGT, AST, ALT, MCV)* 874 medical inpatients (aged 16 or older) screened Incident alcohol withdrawal assessed prospectively during hospitalization in 98 patients with a positive AUDIT score (>=8) *Gamma glutamyltransferase, aspartate aminotransferase, alanine aminotransferase, and mean corpuscular volume

Assessing Validity of an Article about Prognosis Are the results valid? What are the results? How can I apply the results to patient care?

Are the Results Valid? Was the sample representative? Were the subjects sufficiently homogeneous with respect to prognostic risk? Was follow-up sufficiently complete? Were objective and unbiased outcome criteria used?

Was the sample representative? 267 of 1243 admissions were excluded because of incomplete AUDIT questionnaires and lab results. –This likely biased the sample though it is not clear in what direction. –So, whether the study sample was representative of all admissions is unknown. Those who were confused or transferred quickly were excluded. The screened sample included 874 medical inpatients, aged 16 or older.

Was the sample representative? (cont.) The sample that was monitored for withdrawal development included only the 98 subjects (11%) with a positive AUDIT (>=8). –Therefore, the sample does not represent people with an AUDIT <8 who might develop withdrawal.

Were the subjects sufficiently homogeneous with respect to prognostic risk?  Subjects were likely sufficiently homogeneous with respect to withdrawal risk because...  all were eligible for the study from the time of admission.  However, time of last drink was not reported. If highly variable, it might have led to a heterogeneous sample with respect to withdrawal risk.

Was follow-up sufficiently complete? All subjects were followed through the period of risk of developing alcohol withdrawal. –However, the authors did not provide details on whether any subjects were lost to follow-up.

Were objective and unbiased outcome criteria used? Subjects with an AUDIT score of >=8 (a positive test for an alcohol use disorder) were monitored with the CIWA-Ar, an objective outcome measure.

What are the Results? How likely are the outcomes over time? How precise are the estimates of likelihood?

How likely are the outcomes over time?  Of the 98 subjects with positive AUDITs, 17 (17%) experienced clinically significant withdrawal symptoms. All patients with withdrawal had positive AUDITs (>=8; sensitivity 100%). –However, those with AUDIT<8 were not monitored for withdrawal using the objective outcome measure, raising the possibility of overestimated sensitivity. All but 1 patient with withdrawal had abnormal blood test results.

How likely are the outcomes over time? (cont.) Most patients without withdrawal had normal AUDIT scores (specificity 91%). Although a positive AUDIT score plus any 2 abnormal blood tests had a sensitivity of 94% and a specificity of 98%... –fewer than half of patients with this combination had withdrawal.

How precise are the estimates of likelihood? The authors did not provide measures of precision.

How Can I Apply the Results to Patient Care? Were the study patients and their management similar to those in my practice? Was the follow-up sufficiently long? Can I use the results in the management of patients in my practice?

Were the study patients similar to those in my practice? Study patients may have been representative of those on medicine services in general hospitals.

Was the follow-up sufficiently long? The patients were followed until the CIWA-Ar score was <11 for 12 hours. –This is likely long enough that no cases of late withdrawal were missed. –However, longer follow-up would have reduced the likelihood of missing any cases (e.g., 24 hours CIWA- Ar <8). The authors do not report any loss to follow-up.

Can I use the results in the management of patients in my practice? Limitations to this study: Researchers monitored alcohol withdrawal only in subjects with AUDIT >=8 so the study cannot draw conclusions about those with AUDIT<8. A substantial number of patients were excluded because of incomplete AUDITs or blood tests, likely biasing the sample. Follow-up may not have been long enough. The number of patients with symptomatic withdrawal is too small to draw firm conclusions.

Can I use the results in the management of patients in my practice? (cont.) Nonetheless, given that the AUDIT identifies alcohol dependence, it is not surprising that it can also predict who will have alcohol withdrawal. But, most patients with dependence will not have significant withdrawal symptoms. Adding blood tests improves detection of those at risk of withdrawal but may predict only 50%, at best, of withdrawal cases.

Can I use the results in the management of patients in my practice? (cont.) Therefore, alcohol screening in the hospital is mainly useful for… –ruling out risk of withdrawal and –identifying patients who might be ready for alcohol-dependence treatment.