1001 — AUDIT-C Alcohol Misuse Screening and Post-Operative Complications: A Cohort Study of Men Undergoing Major Surgery in VA

Bradley KA (VA Puget Sound HSR&D), DeBenedetti A (VA Puget Sound HSR&D), Sun H (VA Puget Sound HSR&D), Kivlahan D (VA Puget Sound HSR&D), Henderson B (National Surgical Quality Improvement Program), Hawn M (Birmingham REAP), Bishop M (National Surgical Quality Improvement Program), Harris A (Center for Health Care Evaluation), Hawkins E (VA Puget Sound HSR&D)

Objectives:
Patients who drink > 4 drinks daily prior to surgery have a 2-3 fold increased risk of post-operative complications, and pre-operative abstinence decreases this risk. However, there is no consensus on the optimal approach to identify these patients. The VA screens > 90% of outpatients for alcohol misuse annually with the AUDIT-C but the association between alcohol screening results and the risk of post-operative complications is unknown. This study evaluated associations between AUDIT-C scores in the year before VA major surgery and post-operative complications in men.

Methods:
Male patients were eligible for this study if they had major surgery in the VA assessed by the National Surgical Quality Improvement Program (NSQIP) in 2004-6 and completed the AUDIT-C on the Survey of Healthcare Experiences of Patients in the year prior to surgery. Age- and smoking-adjusted prevalence rates were calculated to estimate the absolute risk of 30-day post-operative complications associated with AUDIT-C scores. Logistic regression was used to adjust for demographic and clinical covariates in a stepped fashion. The fully-adjusted model included age, smoking, time from AUDIT-C to surgery, ASA classification, and NSQIP pre-operative covariates associated with the exposure or outcome, excluding those with no impact on the model fit (referent group = low level drinkers).

Results:
Among 9,197 eligible men undergoing major surgery in VA, 1,509 (16.4%) screened positive for alcohol misuse with AUDIT-C scores > = 5. Age- and smoking-adjusted prevalence rates of 30-day post-op complications were 7.7% among nondrinkers (AUDIT-C score 0), 5.3-6.5% among low-level drinkers (AUDIT-C 1-4), 7.7-9.9% among at-risk drinkers (AUDIT-C 5-8), 10.7% among high-risk drinkers (both AUDIT-C 9 and 10), and 13.9-16.6% among highest-risk drinkers (AUDIT-C 11-12). The fully adjusted odds of complications increased as AUDIT-C scores increased: 1.53 (1.17-2.01); 1.69 (1.07-2.66) and 1.92 (1.08-3.43), for at-risk, high- risk and highest-risk drinkers, respectively.

Implications:
The AUDIT-C administered up to a year before major surgery identifies patients at risk for post-operative complications, and risks are greatest for those with the highest scores.

Impacts:
VA surgeons, anesthesiologists, and NSQIP might consider using documented AUDIT-C scores available for most VA outpatients as a pre-operative measure of risk for alcohol-related surgical complications.