Reliability and Validity of the Quantitative Inventory of Alcohol Disorders (QIAD) and the Veracity of Self-Report by Alcoholics

Abstract

The purpose of this study was to investigate a recently developed instrument for alcoholism severity: The Quantitative Inventory of Alcohol Disorders (QIAD). The primary intention was to demonstrate the reliability and validity of the QIAD as a diagnostic tool within the field of alcoholism. A secondary intention was to examine the veracity of alcoholics self-report on the QIAD and other alcohol-related instruments. The subjects for the experimental group were 25 inpatient alcoholics and their spouses. The control group consisted of 21 nonalcoholics and their spouses. All subjects were administered the QIAD, Michigan Alcoholism Screening Test (MAST), and the Alcohol Severity Rating Scale (ASRS). The alcoholics and partners were given the same tests 5 to 8 days after initial testing. The primary therapists for the alcoholics were asked to rate alcoholism severity for each subject using the ASRS. Pearson product moment correlation coefficients were used for the test-retest reliability procedure. Alcoholics scores on the QIAD, MAST, and ASRS were compared with their spouses scores using a test-retest procedure. Nonalcoholics scores on these instruments were also compared with their spouses' scores. Construct and concurrent validity for the QIAD were tested through comparison of QIAD scores of the alcoholics with their corresponding scores on the MAST and ASRS. t-Tests were used to determine differences between alcoholics and nonalcoholics on all three scales. The results of this investigation supported the position that the QIAD is a reliable and valid instrument for measuring alcoholism severity. The QIAD correlated highly for both the alcoholics and their spouses. The test-retest procedure revealed a high level of correlation. A significant difference was found between the QIAD scores of the alcoholics and nonalcoholics. Construct validity was demonstrated by significant correlations between the alcoholics QIAD and MAST scores, both measuring the extent of alcoholism. The QIAD demonstrated concurrent validity by significantly correlating with alcoholics ASRS ratings. High correlations bet ween alcoholic and spouse scores on the QIAD supported the hypothesis that inpatient alcoholics can produce valid responses to self-report questionnaires.