Meta-analysis of DSM alcohol use disorder criteria severities: structural consistency is only 'skin deep'.

BACKGROUND: Item response theory (IRT) analyses of alcohol use disorder (AUD) and other psychological disorders are a predominant method for assessing overall and individual criterion severity for psychiatric diagnosis. However, no investigation has established the consistency of the relative criteria severities across different samples. METHOD: PubMed/Medline, PsycINFO, Web of Science and ProQuest databases were queried for entries relating to alcohol use and IRT. Study data were extracted using a standardized data entry sheet. Consistency of reported criteria severities across studies was analysed using generalizability theory to estimate generalized intraclass correlations (ICCs). RESULTS: A total of 451 citations were screened and 34 papers (30 unique samples) included in the research synthesis. The AUD criteria set exhibited low consistency in the ordering of criteria using both traditional [ICC = 0.16, 95% confidence interval (CI) 0.06-0.56] and generalized (ICC = 0.18, 95% CI 0.15-0.21) approaches. These results were partially accounted for by previously studied factors such as age and type of sample (e.g. clinical v. community), but the largest source of unreliability was the diagnostic instrument employed. CONCLUSIONS: Despite the robust finding of unidimensional structure of AUDs, inconsistency in the relative severities across studies suggests low replicability, challenging the generalizability of findings from any given study. Explicit modeling of well-studied factors like age and sample type is essential and increases the generalizability of findings. Moreover, while the development of structured diagnostic interviews is considered a landmark contribution toward improving psychiatric research, variability across instruments has not been fully appreciated and is substantial.

Towards the characterization and validation of alcohol use disorder subtypes: integrating consumption and symptom data.

BACKGROUND: There is evidence that measures of alcohol consumption, dependence and abuse are valid indicators of qualitatively different subtypes of alcohol involvement yet also fall along a continuum. The present study attempts to resolve the extent to which variations in alcohol involvement reflect a difference in kind versus a difference in degree. METHOD: Data were taken from the 2001-2002 National Epidemiologic Survey of Alcohol and Related Conditions. The sample (51% male; 72% white/non-Hispanic) included respondents reporting past 12-month drinking at both waves (wave 1: n = 33644; wave 2: n = 25186). We compared factor mixture models (FMMs), a hybrid of common factor analysis (FA) and latent class analysis (LCA), against FA and LCA models using past 12-month alcohol use disorder (AUD) criteria and five indicators of alcohol consumption reflecting frequency and heaviness of drinking. RESULTS: Model comparison revealed that the best-fitting model at wave 1 was a one-factor four-class FMM, with classes primarily varying across dependence and consumption indices. The model was replicated using wave 2 data, and validated against AUD and dependence diagnoses. Class stability from waves 1 to 2 was moderate, with greatest agreement for the infrequent drinking class. Within-class associations in the underlying latent factor also revealed modest agreement over time. CONCLUSIONS: There is evidence that alcohol involvement can be considered both categorical and continuous, with responses reduced to four patterns that quantitatively vary along a single dimension. Nosologists may consider hybrid approaches involving groups that vary in pattern of consumption and dependence symptomatology as well as variation of severity within group.