Exploring the predictive power of the unspecific risk category of the Basel Screening Instrument for Psychosis

Early Interv Psychiatry. 2019 Aug;13(4):969-976. doi: 10.1111/eip.12719. Epub 2018 Jul 18.

Abstract

Aim: Ultrahigh risk (UHR) criteria, consisting of brief limited intermittent psychotic symptoms (BLIPS), attenuated psychotic symptoms (APS) and genetic risk and deterioration (GRD) syndrome are the most widely used criteria for assessing the clinical high-risk state for psychosis (CHR-P). The Basel Screening Instrument for Psychosis (BSIP) includes a further risk category, the unspecific risk category (URC). However, little is known about the predictive power of this risk category compared to other risk categories.

Methods: Two hundred CHR-P patients were detected as part of the Früherkennung von Psychosen (FePsy) study using the BSIP. Transition to psychosis was assessed in regular intervals for up to 7 years.

Results: Patients meeting only the URC criterion (n = 40) had a significantly lower risk of transition to psychosis than the UHR group (including BLIPS, APS and GRD) (HR 0.19 [0.05; 0.80] (P = 0.024). Furthermore, the URC only risk group had a lower transition risk than the APS without BLIPS group (P = 0.015) and a trendwise lower risk than the BLIPS group (P = 0.066). However, despite the lower transition risk in the URC only group, there were still two patients (5%) in this group with a later transition to psychosis.

Conclusions: The URC includes patients who have a lower risk of transition than those included by the UHR categories and thereby increases the sensitivity of the BSIP. This offers the possibility of a stratified intervention, with these subjects receiving low intensity follow-up and treatment.

Keywords: follow-up studies; prodromal symptoms; psychotic disorders; risk; sensitivity and specificity.

MeSH terms

  • Adolescent
  • Adult
  • Early Diagnosis
  • Female
  • Follow-Up Studies
  • Genetic Predisposition to Disease / genetics
  • Humans
  • Male
  • Mass Screening / statistics & numerical data
  • Psychiatric Status Rating Scales / statistics & numerical data*
  • Psychotic Disorders / diagnosis*
  • Psychotic Disorders / genetics
  • Psychotic Disorders / psychology
  • Risk Assessment* / statistics & numerical data
  • Young Adult