Psychometric and clinical evaluation of schizophrenia remission criteria in outpatients with psychotic disorders

Abstract

Background: Psychotic disorders such as schizophrenia have debilitating effects on health and functioning. Given symptomatic remission’s recent emergence as a viable treatment goal, the Remission in Schizophrenia Working Group’s criteria (RSWG-cr), based on eight items from the Positive and Negative Syndrome Scale (PANSS-8), are frequently used in clinical and research settings. Against that background, we sought to evaluate the PANSS-8’s psychometric properties and examine the RSWG-cr’s clinical validity among outpatients in Sweden. Methods: Cross-sectional register data were collected from outpatient psychosis clinics in Gothenburg, Sweden. Following confirmatory and exploratory factor analyses of PANSS-8 data (n = 1,744) to assess the PANSS-8’s psychometric properties, internal reliability was evaluated using Cronbach’s alpha. Next, 649 of the patients were classified according to the RSWG-cr and their clinical and demographic characteristics compared. Binary logistic regression was used to estimate odds ratios (OR) and assess each variable’s impact on remission status. Results: The PANSS-8 showed good reliability (α =.85), and the 3D model of psychoticism, disorganization, and negative symptoms presented the best model fit. According to the RSWG-cr, 55% of the 649 patients were in remission; they were also more likely to live independently, be employed, not smoke, not take antipsychotics, and have recently received a health interview and physical examination. Patients living independently (OR = 1.98), who were employed (OR = 1.89), who were obese (OR = 1.61), and who had recently received a physical examination (OR = 1.56) also had an increased likelihood of remission. Conclusions: The PANSS-8 is internally reliable, and, according to the RSWG-cr, remission is associated with variables of interest for patients’ recovery, including living independently and being employed. Although our findings from a large, heterogeneous sample of outpatients reflect everyday clinical practice and reinforce past observations, the directions of those relationships need to be assessed in longitudinal studies.