title: Diagnostic accuracy and confusability analyses: an application to the Diagnostic Interview for Genetic Studies.
abstract: The dominant, contemporary paradigm for developing and refining diagnoses relies heavily on assessing reliability with kappa coefficients and virtually ignores a core component of psychometric practice: the theory of latent structures. This article describes a psychometric approach to psychiatric nosology that emphasizes the diagnostic accuracy and confusability of diagnostic categories. We apply these methods to the Diagnostic Interview for Genetic Studies (DIGS), a structured psychiatric interview designed by the NIMH Genetics Initiative for genetic studies of schizophrenia and bipolar disorder. Our results show that sensitivity and specificity were excellent for both DSM-III-R and RDC diagnoses of major depression, bipolar disorder, and schizophrenia. In contrast, diagnostic accuracy was substantially lower for subtypes of schizoaffective disorder-especially for the DSM-III-R definitions. Both the bipolar and depressed subtypes of DSM-III-R schizoaffective disorder had excellent specificity but poor sensitivity. The RDC definitions also had excellent specificity but were more sensitive than the DSM-III-R schizoaffective diagnoses. The source of low sensitivity for schizoaffective subtypes differed for the two diagnostic systems. For RDC criteria, the schizoaffective subtypes were frequently confused with one another; they were less frequently confused with other diagnoses. In contrast, the DSM-III-R subtypes were often confused with schizophrenia, but not with each other.
authors.affiliation: Harvard Institute of Psychiatric Epidemiology and Genetics, Harvard Medical School Department of Psychiatry, Boston, USA.
authors.forename: S V
authors.initials: SV
authors.lastname: Faraone
authors.forename: M
authors.initials: M
authors.lastname: Blehar
authors.forename: J
authors.initials: J
authors.lastname: Pepple
authors.forename: S O
authors.initials: SO
authors.lastname: Moldin
authors.forename: J
authors.initials: J
authors.lastname: Norton
authors.forename: J I
authors.initials: JI
authors.lastname: Nurnberger
authors.forename: D
authors.initials: D
authors.lastname: Malaspina
authors.forename: C A
authors.initials: CA
authors.lastname: Kaufmann
authors.forename: T
authors.initials: T
authors.lastname: Reich
authors.forename: C R
authors.initials: CR
authors.lastname: Cloninger
authors.forename: J R
authors.initials: JR
authors.lastname: DePaulo
authors.forename: K
authors.initials: K
authors.lastname: Berg
authors.forename: E S
authors.initials: ES
authors.lastname: Gershon
authors.forename: D G
authors.initials: DG
authors.lastname: Kirch
authors.forename: M T
authors.initials: MT
authors.lastname: Tsuang
mesh_terms: D001714:Bipolar Disorder / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology; D003866:Depressive Disorder / Q000175:diagnosis / Q000235:genetics / Q000523:psychology; D006801:Humans; D010552:Personality Assessment / Q000706:statistics & numerical data*; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011594:Psychometrics; D011618:Psychotic Disorders / Q000175:diagnosis / Q000235:genetics / Q000523:psychology; D015203:Reproducibility of Results; D012307:Risk Factors; D012559:Schizophrenia / Q000175:diagnosis / Q000235:genetics*; D012565:Schizophrenic Psychology