Comparison of self-report and biological measures for alcohol, tobacco and illicit drug use in consecutive alcohol-dependent patients visiting a tertiary care centre

Background: Alcohol is a major drug of abuse in patients visiting treatment centres. The self-report is used by clinicians to collect information; however, alcohol-dependent patients may not provide reliable self-reports. Aim: The study aimed to assess the agreement between urinalysis and self-report for licit and illicit drug use in alcohol-dependent patients and to examine the relationship of biochemical measures with self-reported alcohol consumption. Methods: Consecutive patients (N = 199) with current alcohol use fulfilling Diagnostic and Statistical Manual, 4th edition (DSM-IV) criteria for alcohol dependence were included. Recent alcohol and drug use was enquired using a structured questionnaire. The biological measures included urine drug analysis and biochemical liver function tests. Results: Urinalysis revealed the use of opiates, cannabis, nicotine and benzodiazepines in 2.5%, 4.2%, 5.9% and 28.8%, respectively, even though patients reported no use of these drugs. Gamma-glutamyl transferase (GGT) was elevated in 95.2% of patients with self-reported heavy alcohol consumption, whereas it was raised in 60-62.5% of those with low to moderate alcohol use. In heavy drinkers, the biochemical liver markers appeared to corroborate with self-reported alcohol use. Conclusion: This study urges for the use of objective methods to validate the self-report in alcohol-dependent patients, especially for co-occurring nonprescription benzodiazepine and drug use.