Rasch analysis of alcohol abuse and dependence diagnostic criteria in persons with spinal cord injury

Study design: Cross-sectional. Objective: The objective of the study is to examine whether alcohol use disorders should be conceptualized categorically as abuse and dependence as in the 'Diagnostic and Statistical Manual of Mental Disorders' 4th edition or on a single continuum with mild to severe category ratings as in the 'Diagnostic and Statistical Manual of Mental Disorders' 5th edition in people with spinal cord injury (SCI). Setting: United States of America. Methods: Data from 379 individuals who sustained SCI either traumatically or non-traumatically after the age of 18 and were at least 1 year post injury. Rasch analyses used the alcohol abuse and dependence modules of the Structured Clinical Interview for DSM-IV-TR Axis I Disorders Non-patient Edition (SCID-I/NP). Results: Fifty-seven percent (n=166) of the entire sample endorsed criteria for alcohol abuse, and 25% (n=65) endorsed criteria for alcohol dependence. Fit values were generally acceptable except for one item (for example, alcohol abuse criterion 2), suggesting that the items fit the expectation of unidimensionality. Examination of the principal components analysis did not provide support for unidimensionality. The item-person map illustrates poor targeting of items. Conclusions: Alcohol abuse and dependence criterion appear to reflect a unidimensional construct, a finding that supports a single latent construct or factor consistent with the DSM-5 diagnostic model.