Systematic Study of Structured Diagnostic Procedures in Outpatient Psychiatric Rehabilitation: A Three-year, Three-cohort Study of the Stability of Psychiatric Diagnoses.

Background. Psychiatric diagnoses are important for treatment planning. There are a number of current challenges in the area of psychiatric diagnosis with important treatment implications. In this study, we examined the differential usefulness of two semi-structured interviews of differing length compared to clinical diagnoses for generation of diagnoses that did not require modification over the course of treatment. Methods. We performed a three-year, three-cohort study at an outpatient psychiatric rehabilitation facility, comparing the stability of admission diagnoses when generated by unstructured procedures relying on referring clinician diagnosis, the SCID, and the MINI. We examined changes in diagnoses from admission to discharge (averaging 13 weeks) and, during the second two years, convergence between referring clinician diagnoses and those generated by structured interviews. The same three interviewers examined all patients in all three phases of the study. Results. Admission and discharge diagnoses were available for 313 cases. Diagnoses generated with the unstructured procedure were changed by discharge 74 percent of the time, compared to four percent for SCID diagnoses and 11 percent for MINI diagnoses. Referring clinician diagnoses were disconfirmed in Years 2 and 3 in 56 percent of SCID cases and 44 percent of MINI cases. The distinctions between unipolar and bipolar disorders were particular points of disagreement, with similar rates of under and over-diagnosis of bipolar disorder. The rate of confirmation of referring clinician diagnoses of schizoaffective disorder was 10 percent with the SCID and 11 percent with the MINI. Discussion. In this setting, there appears to be a reasonable trade-off between brevity and accuracy through the use of the MINI compared to the SCID, with substantial improvements in stability of diagnoses compared to clinician diagnoses. Clinical diagnoses were minimally overlapping with the results of structured diagnoses, suggesting that structured assessment, particularly early in the illness or in short term treatment settings, may improve treatment planning.