Analysis of alcohol use clusters among subcritically injured emergency department patients

1) To cluster patients according to self-reported drinking patterns using cluster analysis; 2) to externally validate clustered groups on variables related to drinking but not used in the cluster analysis; and 3) to use the clustered patients' responses to alcohol consumption questions to develop a brief screening tool emergency physicians can use to identify patients in need of referral or intervention related to potentially hazardous alcohol consumption.

A self-report battery was administered to 95 subcritically injured patients. Patients also were saliva alcohol-tested upon arrival to the ED. Using the patients' self-reported quantity, frequency of alcohol consumption, and frequency of having > or = 6 drinks on a drinking occasion, patients were categorized into 3 groups using cluster analysis. The 3 clusters were externally validated using injury-related variables, alcohol-related consequences, and the patients' reported readiness to change drinking. A screening tool was developed using cutoff values reported by the patients' answers to drinking pattern questions.

Fifty-nine patients were alcohol-negative, and 36 tested alcohol-positive (i.e., > 4 mmol/L [> 20 mg/dL]) or had elevated scores on an alcohol problem screening instrument. Three distinct drinking pattern clusters were found. Clusters were validated using discriminant function analysis and multivariate analyses of variance to confirm cluster classifications. Steady and high-intensity drinkers reported more alcohol-related negative consequences, and high-intensity drinkers indicated they would consider changing their drinking. The screening tool correctly classified 97% of the patient sample into their respective clusters.

Using the drinking pattern questions in the clustering procedure was effective for grouping injured patients into clusters that could be differentiated on other drinking-related variables. The resulting screening tool can be used in the ED setting to screen patients for further assessment and intervention. The readiness-to-change results support the assertion that the injury event provides a "teachable moment" for subcritically injured patients whose injury may be related to their alcohol consumption.