The construct and measurement equivalence of cocaine and opioid dependences: A National Drug Abuse Treatment Clinical Trials Network (CTN) study

Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Duke Clinical Research Institute, Durham, NC 27710, USA.
Drug and alcohol dependence (Impact Factor: 3.42). 06/2009; 103(3):114-23. DOI: 10.1016/j.drugalcdep.2009.01.018
Source: PubMed


Although DSM-IV criteria are widely used in making diagnoses of substance use disorders, gaps exist regarding diagnosis classification, use of dependence criteria, and effects of measurement bias on diagnosis assessment. We examined the construct and measurement equivalence of diagnostic criteria for cocaine and opioid dependences, including whether each criterion maps onto the dependence construct, how well each criterion performs, how much information each contributes to a diagnosis, and whether symptom-endorsing is equivalent between demographic groups.
Item response theory (IRT) and multiple indicators-multiple causes (MIMIC) modeling were performed on a sample of stimulant-using methadone maintenance patients enrolled in a multisite study of the National Drug Abuse Treatment Clinical Trials Network (CTN) (N=383). Participants were recruited from six community-based methadone maintenance treatment programs associated with the CTN and major U.S. providers. Cocaine and opioid dependences were assessed by DSM-IV Checklist.
IRT modeling showed that symptoms of cocaine and opioid dependences, respectively, were arrayed along a continuum of severity. All symptoms had moderate to high discrimination in distinguishing drug users between severity levels. "Withdrawal" identified the most severe symptom of the cocaine dependence continuum. MIMIC modeling revealed some support for measurement equivalence.
Study results suggest that self-reported symptoms of cocaine and opioid dependences and their underlying constructs can be measured appropriately among treatment-seeking polysubstance users.

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    • "ROC-AUC denotes the level of accuracy in classifying cases and noncases of an SUD by taking into account the trade-off between sensitivity and specificity. An IRT approach was included to provide psychometric properties of substance-specific screening questions for ROC-AUC [28] [29]. Both IRT and ROC-AUC results for the five substances demonstrate the potential feasibility of identifying " a core set of substance dependence items " as a simplified screen to facilitate detection of alcohol or drug disorders [14]. "
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    ABSTRACT: Objective: The objective was to identify a potential core set of brief screeners for the detection of individuals with a substance use disorder (SUD) in medical settings. Method: Data were from two multisite studies that evaluated stimulant use outcomes of an abstinence-based contingency management intervention as an addition to usual care (National Drug Abuse Treatment Clinical Trials Network trials 006-007). The sample comprised 847 substance-using adults who were recruited from 12 outpatient substance abuse treatment settings across the United States. Alcohol and drug use disorders were assessed by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Checklist. Data were analyzed by factor analysis, item response theory (IRT), sensitivity and specificity procedures. Results: Comparatively prevalent symptoms of dependence, especially inability to cut down for all substances, showed high sensitivity for detecting an SUD (low rate of false negative). IRT-defined severe (infrequent) and low discriminative items, especially withdrawal for alcohol, cannabis and cocaine, had low sensitivity in identifying cases of an SUD. IRT-defined less severe (frequent) and high discriminative items, including inability to cut down or taking larger amounts than intended for all substances and withdrawal for amphetamines and opioids, showed good-to-high values of area under the receiver operating characteristic curve in classifying cases and noncases of an SUD. Conclusion: Findings suggest the feasibility of identifying psychometrically reliable substance dependence symptoms to develop a two-item screen for alcohol and drug disorders.
    General hospital psychiatry 07/2012; 35(1). DOI:10.1016/j.genhosppsych.2012.06.014 · 2.61 Impact Factor
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    • "Of note, IICs reveal crucial evidence for selecting " core items " for an assessment tool (Edelen and Reeve, 2007); when such information is overlooked, conclusions can be limited or biased. For example, one IRT analysis has shown that withdrawal was the most severe item among all cocaine dependence criteria, but additional analyses of IICs revealed its very low level of precision, indicating that it is an unreliable item for measuring cocaine dependence; on the other hand, time spent was revealed by IICs as the most reliable, informative item, implying that time spent is a useful screener for identifying cocaine users with cocaine dependence problems (Wu et al., 2009c). Given the scarcity of IIC data to inform item-level reliability or redundancy in assessing MUDs, the first aim addresses item-level redundancy for MUD criteria. "
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    ABSTRACT: While item response theory (IRT) research shows a latent severity trait underlying response patterns of substance abuse and dependence symptoms, little is known about IRT-based severity estimates in relation to clinically relevant measures. In response to increased prevalences of marijuana-related treatment admissions, an elevated level of marijuana potency, and the debate on medical marijuana use, we applied dimensional approaches to understand IRT-based severity estimates for marijuana use disorders (MUDs) and their correlates while simultaneously considering gender- and race/ethnicity-related differential item functioning (DIF). Using adult data from the 2008 National Survey on Drug Use and Health (N = 37,897), Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for MUDs among past-year marijuana users were examined by IRT, logistic regression, and multiple indicators-multiple causes (MIMIC) approaches. Among 6917 marijuana users, 15% met criteria for a MUD; another 24% exhibited subthreshold dependence. Abuse criteria were highly correlated with dependence criteria (correlation = 0.90), indicating unidimensionality; item information curves revealed redundancy in multiple criteria. MIMIC analyses showed that MUD criteria were positively associated with weekly marijuana use, early marijuana use, other substance use disorders, substance abuse treatment, and serious psychological distress. African Americans and Hispanics showed higher levels of MUDs than Whites, even after adjusting for race/ethnicity-related DIF. The redundancy in multiple criteria suggests an opportunity to improve efficiency in measuring symptom-level manifestations by removing low-informative criteria. Elevated rates of MUDs among African Americans and Hispanics require research to elucidate risk factors and improve assessments of MUDs for different racial/ethnic groups.
    06/2012; 21(2):117-33. DOI:10.1002/mpr.1354
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    • "The results, taken together for all substances examined in this study, suggest the pattern of a single dimension is consistent, but in different populations, using different instruments, the precise order of severity and discrimination parameters varies. The relative ranking of the criteria in terms of severity and discrimination may well change developmentally over time, accounting for differences between the present study conducted in a general population of adults and the study based on adolescents in the general population (Wu et al., 2009 "
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    ABSTRACT: Prior research has demonstrated the dimensionality of alcohol, nicotine and cannabis use disorders criteria. The purpose of this study was to examine the unidimensionality of DSM-IV cocaine, amphetamine and prescription drug abuse and dependence criteria and to determine the impact of elimination of the legal problems criterion on the information value of the aggregate criteria. Factor analyses and Item Response Theory (IRT) analyses were used to explore the unidimensionality and psychometric properties of the illicit drug use criteria using a large representative sample of the U.S. population. All illicit drug abuse and dependence criteria formed unidimensional latent traits. For amphetamines, cocaine, sedatives, tranquilizers and opioids, IRT models fit better for models without legal problems criterion than models with legal problems criterion and there were no differences in the information value of the IRT models with and without the legal problems criterion, supporting the elimination of that criterion. Consistent with findings for alcohol, nicotine and cannabis, amphetamine, cocaine, sedative, tranquilizer and opioid abuse and dependence criteria reflect underlying unitary dimensions of severity. The legal problems criterion associated with each of these substance use disorders can be eliminated with no loss in informational value and an advantage of parsimony. Taken together, these findings support the changes to substance use disorder diagnoses recommended by the American Psychiatric Association's DSM-5 Substance and Related Disorders Workgroup.
    Drug and alcohol dependence 09/2011; 122(1-2):38-46. DOI:10.1016/j.drugalcdep.2011.09.004 · 3.42 Impact Factor
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