Staging and profiling for schizophrenia spectrum disorders: Inter-rater reliability after a short training course

Objective: Clinical staging and profiling have been proposed as a new approach in order to refine the diagnostic assessment of schizophrenia spectrum disorders. However, only limited evidence is available for the inter-rater reliability of the clinical staging and profiling model. The aim of the present study was therefore to determine the inter-rater reliability of the clinical staging and profiling model for schizophrenia spectrum disorders, and to investigate whether a short course can improve inter-rater reliability. Methods: Consecutively recruited inpatients with schizophrenia spectrum disorders were included between January 2015 and January 2016 (study 1), and between March 2018 and October 2018 (study 2). By contrast with the assessors in study 1, all the assessors in study 2 were trained in clinical staging and profiling. We used the clinical staging model proposed by McGorry and identified profile characteristics. Inter-rater reliability was measured using the Intraclass Correlation Coefficient (ICC). Results: The ICC score for clinical staging in study 1 was moderate (0.578). It improved considerably in study 2 (0.757). In general, the ICC scores for the profile characteristics in studies 1 and 2 ranged from poor to sufficient (0.123–0.781). Conclusion: This study demonstrated that inter-rater reliability in clinical staging was sufficient after training. However, inter-rater reliability for clinical profile characteristics was highly variable. The general implementation of the clinical staging model for schizophrenia spectrum disorders is therefore feasible but clinical profile characteristics should be used with caution.