[Skip to Content]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address 35.172.195.49. Please contact the publisher to request reinstatement.
[Skip to Content Landing]
Original Investigation
May 2017

Development and Validation of a Clinically Based Risk Calculator for the Transdiagnostic Prediction of Psychosis

Author Affiliations
  • 1Early Psychosis: Interventions and Clinical Detection Lab, Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, England
  • 2Outreach and Support in South London Service, South London and the Maudsley National Health Service Foundation Trust, London, England
  • 3National Institute for Health Research Biomedical Research Centre for Mental Health, IoPPN, King’s College London, London, England
  • 4Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
  • 5Department of Biostatistics, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, England
  • 6Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, England
JAMA Psychiatry. 2017;74(5):493-500. doi:10.1001/jamapsychiatry.2017.0284
Key Points

Question  Can we improve the detection of individuals at risk of developing psychosis among patients accessing secondary mental health care?

Finding  This clinical register-based cohort study of 91 199 patients receiving a first index diagnosis of nonorganic and nonpsychotic mental disorder developed and externally validated an online individualized risk calculator tool, based on simple predictor variables that are easily and routinely collected in clinical settings, for the transdiagnostic prediction of psychosis in secondary mental health care.

Meaning  This individualized risk calculator tool can be used by clinicians and researchers, facilitating the prediction of psychosis and the subsequent implementation of preventive focused interventions.

Abstract

Importance  The overall effect of At Risk Mental State (ARMS) services for the detection of individuals who will develop psychosis in secondary mental health care is undetermined.

Objective  To measure the proportion of individuals with a first episode of psychosis detected by ARMS services in secondary mental health services, and to develop and externally validate a practical web-based individualized risk calculator tool for the transdiagnostic prediction of psychosis in secondary mental health care.

Design, Setting, and Participants  Clinical register-based cohort study. Patients were drawn from electronic, real-world, real-time clinical records relating to 2008 to 2015 routine secondary mental health care in the South London and the Maudsley National Health Service Foundation Trust. The study included all patients receiving a first index diagnosis of nonorganic and nonpsychotic mental disorder within the South London and the Maudsley National Health Service Foundation Trust in the period between January 1, 2008, and December 31, 2015. Data analysis began on September 1, 2016.

Main Outcomes and Measures  Risk of development of nonorganic International Statistical Classification of Diseases and Related Health Problems, Tenth Revision psychotic disorders.

Results  A total of 91 199 patients receiving a first index diagnosis of nonorganic and nonpsychotic mental disorder within South London and the Maudsley National Health Service Foundation Trust were included in the derivation (n = 33 820) or external validation (n = 54 716) data sets. The mean age was 32.97 years, 50.88% were men, and 61.05% were white race/ethnicity. The mean follow-up was 1588 days. The overall 6-year risk of psychosis in secondary mental health care was 3.02 (95% CI, 2.88-3.15), which is higher than the 6-year risk in the local general population (0.62). Compared with the ARMS designation, all of the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnoses showed a lower risk of psychosis, with the exception of bipolar mood disorders (similar risk) and brief psychotic episodes (higher risk). The ARMS designation accounted only for a small proportion of transitions to psychosis (n = 52 of 1001; 5.19% in the derivation data set), indicating the need for transdiagnostic prediction of psychosis in secondary mental health care. A prognostic risk stratification model based on preselected variables, including index diagnosis, age, sex, age by sex, and race/ethnicity, was developed and externally validated, showing good performance and potential clinical usefulness.

Conclusions and Relevance  This online individualized risk calculator can be of clinical usefulness for the transdiagnostic prediction of psychosis in secondary mental health care. The risk calculator can help to identify those patients at risk of developing psychosis who require an ARMS assessment and specialized care. The use of this calculator may eventually facilitate the implementation of an individualized provision of preventive focused interventions and improve outcomes of first episode psychosis.

×