In psychiatric emergencies, there is a high premium on rapid assessment, acuity categorization and objectivity in decisions regarding the disposition of patients. The Crisis Triage Rating Scale (CTRS), a 3-item clinician-rated instrument, has demonstrated validity in determining the disposal of patients in psychiatric emergency settings. However, its utility has not been evaluated in Nigeria.

This study aimed to assess the validity of the CTRS in predicting the disposal (need for hospitalisation or out-patient treatment) of patients presenting to a psychiatric emergency unit in Nigeria.

The CTRS was administered to consecutively presenting patients (N=247) at the Emergency Unit of the Federal Neuro-Psychiatric Hospital, Yaba, Lagos. Following a comprehensive psychiatric evaluation, clinicians blinded to the CTRS scores made appropriate decisions regarding the disposal of the patients. The ability of the CTRS to predict the need for hospitalisation at different threshold scores, compared with clinical judgement as criterion, was determined statistically.

The optimal threshold on the CTRS for detecting the need for hospitalisation is a cut-off score of 9 as it has the best trade-off with a sensitivity of 0.94 and specificity of 0.89. At this threshold, the overall misclassification rate is 0.09, while the area under the Receiver operating characteristics curve is 0.95. The positive predictive validity for the assessment of disposal at the optimum threshold is 0.91.

The CTRS is a useful tool in determining the disposition of patients presenting to psychiatric emergency service in Nigeria