Predictive validity of clinical AUDIT-C alcohol screening scores and changes in scores for three objective alcohol-related outcomes in a Veterans Affairs population

Aims: To evaluate the association between Alcohol Use Disorder Identification Test-Consumption (AUDIT-C) alcohol screening scores, collected as part of routine clinical care, and three outcomes in the following year (Aim 1), and the association between changes in AUDIT-C risk group at 1-year follow-up and the same outcomes in the subsequent year (Aim 2).

Design: Cohort study.

Setting: Twenty-four US Veterans Affairs (VA) healthcare systems (2004-07), before systematic implementation of brief intervention.

Participants: A total of 486 115 out-patients with AUDIT-Cs documented in their electronic health records (EHRs) on two occasions ≥ 12 months apart ('baseline' and 'follow-up').

Measurements: Independent measures were baseline AUDIT-C scores and change in standard AUDIT-C risk groups (no use, low-risk use and mild, moderate, severe misuse) from baseline to follow-up. Outcome measures were (1) high-density lipoprotein cholesterol (HDL), (2) alcohol-related gastrointestinal hospitalizations ('GI hospitalizations') and (3) physical trauma, each in the years after baseline and follow-up.

Findings: Baseline AUDIT-C scores had a positive association with outcomes in the following year. Across AUDIT-C scores 0-12, mean HDL ranged from 41.4 [95% confidence interval (CI) = 41.3-41.5] to 53.5 (95% CI = 51.4-55.6) mg/l, and probabilities of GI hospitalizations from 0.49% (95% CI = 0.48-0.51%) to 1.8% (95% CI = 1.3-2.3%) and trauma from 3.0% (95% CI = 2.95-3.06%) to 6.0% (95% CI = 5.2-6.8%). At follow-up, patients who increased to moderate or severe alcohol misuse had consistently higher mean HDL and probabilities of subsequent GI hospitalizations or trauma compared with those who did not (P-values all < 0.05). For example, among those with baseline low-risk use, in those with persistent low-risk use versus severe misuse at follow-up, the probabilities of subsequent trauma were 2.65% (95% CI = 2.54-2.75%) versus 5.15% (95% CI = 3.86-6.45%), respectively. However, for patients who decreased to lower AUDIT-C risk groups at follow-up, findings were inconsistent across outcomes, with only mean HDL decreasing in most groups that decreased use (P-values all < 0.05).

Conclusions: When AUDIT-C screening is conducted in clinical settings, baseline AUDIT-C scores and score increases to moderate-severe alcohol misuse at follow-up screening appear to have predictive validity for HDL cholesterol, alcohol-related gastrointestinal hospitalizations and physical trauma. Decreasing AUDIT-C scores collected in clinical settings appear to have predictive validity for only HDL.