TEST-RETEST RELIABILITY OF THE DIAGNOSTIC INTERVIEW SCHEDULE FOR CHILDREN (DISC-2.1) - PARENT, CHILD, AND COMBINED ALGORITHMS

Background: Previous research has not compared the psychometric proper ties of diagnostic interviews of community samples and clinically refe rred subjects within a single Study. As part of a multisite cooperativ e agreement study funded by the National Institute of Mental Health, 9 7 families with clinically referred children and 278 families identifi ed through community sampling procedures participated in a test-retest study of version 2.1 of the Diagnostic Interview Schedule for Childre n (DISC 2.1). Methods: The DISC was separately administered to childre n and parents, and diagnoses were derived from computer algorithms key ed to DSM-III-R criteria. Three sets of diagnoses were obtained, based on parent information only (DISC-P), child information only (DISC-C), and information from either or both (DISC-PC). Results: Test-retest r eliabilities of the DISC-PC ranged from moderate to substantial for di agnoses in the clinical sample. Test-retest kappa coefficients were hi gher for the clinical sample than for the community sample. The DISC-P C algorithm generally had higher reliabilities than the algorithms tha t relied on single informants. Unreliability was primarily due to diag nostic attenuation at time 2. Attenuation was greatest among child inf ormants and less severe cases and in the community sample. Conclusions : Test-retest reliability findings were consistent with or superior to those reported in previous studies. Results support the usefulness of the DISC in further clinical and epidemiologic research; however, clo sely spaced or repeated DISC interviews may result in significant diag nostic attenuation on retest. Further studies of the test-retest atten uation phenomena are needed, including careful examination of the chil d, family, and illness characteristics of diagnostic stability.