Exploring construct validity of clinical staging in schizophrenia spectrum disorders in an acute psychiatric ward.

Objective: clinical staging and profiling of schizophrenia spectrum disorders has been proposed to describe and define the heterogenous course of disease. We examined the construct validity of clinical staging in schizophrenia spectrum disorders by measuring differences in distribution and severity of relevant clinical profilers and therapeutic improvement (HoNOS) across clinical stages.

Methods: we performed a prospective cross-sectional study with 258 inpatiënts who met DSM-IV criteria for schizophrenia spectrum disorders, recruited in an acute ward of a psychiatric hospital from 1-1-2015 until 31-12-2016. All patients (N=258) were assigned to a clinical stage, according to the criteria described by McGorry and clinical profilers were determined. Therapeutic improvement was assessed by measuring change in differences in HoNOS score during admission.

Results: significant higher severity scores of clinical profilers were found in more advanced stages compared to earlier stages. This pattern was apparent in the clinical profilers negative symptoms (F=4.56, P<0.01), number of psychotic episodes last year (F=13.65, P<0.01), compliance (F=2.76, P<0.05), work and daily activities (F=9.85, P<0.001), living situation (F=3.71, P<0.05), support of close relatives (F=9.38, P<0.001) and pre-morbid functioning (F=7.33, P<0.001). Judicial background was less prevalent in earlier stages compared to more advanced disease stages. No differences in therapeutic improvement (HoNOS) were found between clinical stages.

Conclusion: this study demonstrates that clinical staging in schizophrenia spectrum disorders has an acceptable construct validity between earlier and more chronic stages of disease. Several clinical profilers increase in more advanced stages compared to earlier clinical stages, which supports construct validity.