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Article Excerpt
FOLLOWING THE RECOGNITION of alcoholism as a medical illness (Jellinek, 1952) and before the advent of Diagnostic and Statistical Manual (DSM-IV; American Psychiatric Association, 1994) criteria for alcohol dependence, researchers attempted to define the alcohol-dependence syndrome (Edwards and Gross, 1976; Feighner et al., 1972). Although there was not universal agreement about the components of this syndrome, most experts believed that key symptoms included impaired control over alcohol, alcohol-seeking behavior, tolerance, withdrawal, and awareness of a compulsion to consume alcohol. The Alcohol Dependence Scale (ADS; Skinner and Allen, 1982) was designed as a self-report measure assessing this complex of symptoms to yield a continuous score reflecting the degree to which the syndrome was present and its relative severity (i.e., a continuous vs. categorical measure of dependence). Obviously, DSM-IV alcohol-dependence criteria also include most of these criteria and are now widely accepted as the gold standard for diagnosis of alcohol dependence, despite the fact that they are based on expert consensus rather than empirical derivation.
A number of studies in the past 20 years have examined the properties of the ADS in regard to its factor structure, its ability to predict outcomes, and the cutpoints on the scale that should be used to indicate the presence of alcohol dependence (Allen et al., 1994; Kivlahan et al., 1989; Maisto et al., 2003; Ross et al., 1990; Skinner and Allen, 1982; Willenbring and Bielinski, 1994). The ADS did not accurately predict relapse after discharge and entry into outpatient aftercare treatment in a sample of alcohol-dependent inpatients (Kivlahan et al., 1989). In a sample of 501 individuals presenting for alcohol or drug treatment and given a structured diagnostic interview for DSM, Third Edition (DSM-III; American Psychiatric Association, 1980), alcohol dependence, a cutpoint of 9 on the ADS showed a sensitivity of 91% and a specificity of 82% in detecting alcohol dependence as determined by diagnostic interview (Ross et al., 1990). However, the ADS had poor sensitivity and specificity in a sample of medically ill, alcohol-dependent veterans (Willenbring and Bielinski, 1994).
No prior studies have specifically compared the ADS with DSM-IV criteria for alcohol dependence based on structured diagnostic interview, nor have any studies examined the capacity of the ADS to distinguish physiological from nonphysiological dependence. Determination of the physiological component of alcohol dependence holds some prognostic importance because physiological dependence has been associated with more severe drug and alcohol problems in prospective studies (Schuckit et al., 2003).
Skinner and Allen (1982) found that separating their sample (N = 225) into quartiles based on ADS score created four groups that scored differently in regard to their own perceptions about the seriousness of their alcohol problems, had differential rates of treatment engagement, and had different rates of digestive disorders. The findings regarding differences between these quartiles subsequently have not been evaluated nor have empirically derived gender-specific cutpoints been established to screen for physiological dependence. The purpose of the current study is to test the concurrent validity of the ADS, as well as several of its constituent parts, as a measure of severity among a large sample of alcohol-dependent, treatment-seeking individuals from the COMBINE (Combining Pharmacotherapies and Behavioral Interventions for Alcohol Dependence) Study (Anton et al., 2006; COMBINE Study Research Group, 2003).
Method
Overview of COMBINE Study
The COMBINE Study is an 11-site, randomized, placebo-controlled, clinical trial to test 16 weeks of active treatment using naltrexone (ReVia) and acamprosate (Campral) alone and in combination. Most participants received nine brief sessions delivered by medically trained providers to promote sobriety and enhance medication adherence. Half the participants were also randomized to individualized psychotherapy (up to 20 sessions) integrating elements of the successful behavioral interventions from Project MATCH (Matching Alcoholism Treatments to Client Heterogeneity). COMBINE evaluated the efficacy of the two most promising medications (naltrexone and acamprosate), both singly and together, when combined with different intensities of behavioral therapies.
Subjects
Individuals randomized into the COMBINE Study formed the subject pool for the present investigation. Telephone screens were conducted with 4,965 treatment-seeking volunteers who were evaluated for alcohol consumption criteria. Among the individuals screened, 2,928 did not meet entry criteria (see later discussion) on the telephone screen. The remaining 2,037 individuals were invited to study centers for in-person baseline evaluations. An additional 654 individuals failed to meet study entry criteria (see later discussion) during these evaluations. The predominant reasons (in order of occurrence) for failure to reach randomization were (1) "dropped-out of the evaluation after beginning the process," (2) "already established abstinence for a duration that exceeded the maximum threshold for study entry," and (3) "no-show for any post-telephone screening assessment session." The final randomized sample comprised 1,383 subjects, with complete ADS data available for 1,372 of the subjects. These 1,372 individuals remained in the final sample for the present investigation.
All subjects gave informed consent before participation in the research. Key inclusion criteria for entry into the study were age 18 years or older, current DSM-IV diagnosis of alcohol dependence, drinking a minimum of 14 standard drinks (for women) or 21 standard drinks (for men) on average per week during a 30-day period in the 90 days prior to initiation of abstinence before randomization, 2 or more days of heavy drinking (4 or more drinks for women; 5 or more drinks for men) during a consecutive 30-day period within the 90 days before baseline evaluation,...
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