Patient Impairment Lexicon: a validation study

Growth of managed behavioral health organizations (MBHOs) has increased the need for a standardized diagnostic language. The Patient Impairment Lexicon (PIL; Goodman, Brown, & Deitz, 1992, 1996) is intended to address this need. Augmenting previous psychometric assessment (Klewicki, Bjorck, Leucht, & Goodman, 1998), the current study evaluated the PIL's construct validity. Sixteen raters completed impairment inventories; diagnoses based on the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised (DSM-III-R; American Psychiatric Association, 1987); and independent measures of psychiatric functioning for patients in 20 vignettes. Overall rater accuracy was significantly higher for PIL impairments than for diagnoses. As predicted, there were positive correlations between PIL impairments and psychiatric functioning for all 20 vignettes, 11 of which were significant. Results remained significant after controlling variance due to: (a) raters' past experience with similar patients and (b) vignette imaginability. Findings are discussed in terms of MBHO applications and future PIL research.