RELIABILITY AND CLINICAL VALIDITY OF UM-CIDI DSM-III-R GENERALIZED ANXIETY DISORDER

This is the first in a series of reports on the long-term test-retest reliability and procedural validity of the UM-CIDI, a modified version of the Composite International Diagnostic Interview used in the US Na tional Comorbidity Survey (NCS). This report focuses on DSM-III-R Gene ralized Anxiety Disorder (GAD). The NCS administered the UM-CIDI to a nationally representative sample of 8098 respondents in the age range 15-54. A subsample of 36 respondents was subsequently selected for cli nical reappraisal of GAD, consisting of reinterviewing by a clinical r eappraisal interviewer who blindly readministered the GAD section of t he UM-CIDI followed by an expanded version of the GAD section of the S tructured Clinical Interview for DSM-III-R (SCID). The test-retest rel iability of UM-CIDI/DSM-III-R lifetime GAD is Kappa = .53. When the re quirement that the worries be excessive or unrealistic (A2) is removed , as in ICD-10 and partially in DSM-IV, reliability increases to Kappa = .78. The concordance between the baseline UM-CIDI diagnosis and the SCID diagnosis is Kappa = .35, while the cross-sectional concordance is Kappa = .47 (.66 when the Criterion A2 requirement is removed). Ite m-level analysis shows that lack of concordance between the UM-CIDI an d the SCID is due largely to Criteria A2 and D. The A2 problem could b e addressed either by deemphasizing the cognitive-evaluative component of GAD as in ICD-10, or by removing consideration of the term ''unrea listic'' from the criterion as in DSM-IV and more clearly specifying t he meaning of the term ''excessive''. These options require further re search on similarities and differences in risk factors, course, family history, and treatment response of more narrowly and broadly defined GAD. The Criterion D problem is due to lack of clarity. in what consti tutes a symptom occurring ''often''. This is clarified in DSM-IV. It i s likely that this clarification will make it possible to develop more precisely structured questions to evaluate Criterion D in subsequent revisions of the UM-CIDI, resulting in improved reliability and validi ty.