Design and validation of standardized clinical and functional remission criteria in schizophrenia.

Abstract

BackgroundInternational Remission Criteria (IRC) for schizophrenia were developed recently by a group of internationally known experts. The IRC detect only 10%–30% of cases and do not cover the diversity of forms and social functioning. Our aim was to design a more applicable tool and validate its use – the Standardized Clinical and Functional Remission Criteria (SCFRC).MethodsWe used a 6-month follow-up study of 203 outpatients from two Moscow centers and another further sample of stable patients from a 1-year controlled trial of atypical versus typical medication. Diagnosis was confirmed by International Classification of Diseases Version 10 (ICD10) criteria and the Mini-International Neuropsychiatric Interview (MINI). Patients were assessed by the Positive and Negative Syndrome Scale, including intensity threshold, and further classified using the Russian domestic remission criteria and the level of social and personal functioning, according to the Personal and Social Performance Scale (PSP). The SCFRC were formulated and were validated by a data reanalysis on the first population sample and on a second independent sample (104 patients) and in an open-label prospective randomized 12-month comparative study of risperidone long-acting injectable (RLAI) versus olanzapine.ResultsOnly 64 of the 203 outpatients (31.5%) initially met the IRC, and 53 patients (26.1%) met the IRC after 6 months, without a change in treatment. Patients who were in remission had episodic and progressive deficit (39.6%), or remittent (15%) paranoid schizophrenia, or schizoaffective disorder (17%). In addition, 105 patients of 139 (51.7%), who did not meet symptomatic IRC, remained stable within the period. Reanalysis of data revealed that 65.5% of the patients met the SCFRC. In the controlled trial, 70% of patients in the RLAI group met the SCFRC and only 19% the IRC. In the routine treatment group, 55.9% met the SCFRC and only 5.7% the IRC. Results of the further independent sample demonstrated that 35% met the IRC, 65% the SCFRC, and 56% of patients met both the symptomatic and functional criteria. In the controlled trial of RLAI and olanzapine, 40% and 35% of patients, respectively, met the IRC, while 70% and 55%, respectively, met the SCFRC.ConclusionIn schizophrenia outpatients, a greater proportion of stable cases is detected in remission by SCFRC in comparison with IRC. The SCFRC were more sensitive to the full spectrum of schizophrenia. The SCFRC appear to be valid as a tool and clinically useful as they produce a comprehensive assessment of treatment effectiveness for a wide range of patients.