Reliability and validity of the Thai self-report version of the Yale-Brown Obsessive-Compulsive Scale-Second Edition

Awareness of illness moderates self-assessment of psychotic symptoms

OBJECTIVE

Self-reports or patient-reported outcome measures are seldom used in psychosis due to concerns about the ability of patients to accurately report their symptomatology, particularly in cases of low awareness of illness. The aim of this study was to assess the effect of insight on the accuracy of self-reported psychotic symptoms using a computerized adaptive testing tool (CAT-Psychosis).

METHODS

A secondary analysis of data drawn from the CAT-Psychosis development and validation study was performed. The Brief Psychiatric Rating Scale and the Scale of Unawareness of Mental Disorders were administered by clinicians. Patients completed the self-reported version of the CAT-Psychosis. Patients were median-split regarding their insight level to compare the correlation between the two psychosis severity measures. A subgroup sensitivity analysis was performed only on patients with schizophrenia spectrum disorders.

RESULTS

A total of 159 patients with a psychotic disorder who completed both CAT-Psychosis and Scale of Unawareness of Mental Disorders were included. For the whole sample, CAT-Psychosis scores showed convergent validity with Brief Psychiatric Rating Scale ratings (r = 0.517, 95% confidence interval = [0.392, 0.622], p < 0.001). Insight was found to moderate this correlation (β = -0.511, p = 0.005), yet agreement between both measures remained statistically significant for both high (r = 0.621, 95% confidence interval = [0.476, 0.733], p < 0.001) and low insight patients (r = 0.408, 95% confidence interval = [0.187, 0.589], p < 0.001), while psychosis severity was comparable between these groups (for Brief Psychiatric Rating Scale: U = 3057, z = -0.129, p = 0.897; disorganization: U = 2986.5, z = -0.274, p = 0.784 and for CAT-Psychosis: U = 2800.5, z = -1.022, p = 0.307). Subgroup of patients with schizophrenia spectrum disorders showed very similar results.

CONCLUSIONS

Insight moderates the correlation between self-reported and clinician-rated severity of psychosis, yet CAT-Psychosis remains valid in patients with both high and low awareness of illness.

Clinical reappraisal of the Composite International Diagnostic Interview Version 3.0 in the Saudi National Mental Health Survey

OBJECTIVES

The DSM-IV diagnoses generated by the fully structured lay-administered Composite International Diagnostic Interview Version 3.0 (CIDI 3.0) in the Saudi National Mental Health Survey (SNMHS) were compared to diagnoses based on blinded clinical reappraisal interviews.

METHODS

Telephone follow-up interviews were administered using the clinician-administered non-patient edition of the Structured Clinical Interview for DSM-IV (SCID) in separate sub-samples of SNMHS respondents who screened positive for four disorders that are of special importance in Arab countries: obsessive-compulsive disorder, separation anxiety disorder, social phobia, and major depressive episode.

RESULTS

Initial diagnoses based on the CIDI were found to have higher prevalence than those based on the SCID for all four disorders. For reasons having to do with respondent denial of symptoms in the SCID reported in the CIDI, we interpreted these differences as due more to under-diagnoses in the SCID than over-diagnoses in the CIDI. Nonetheless, CIDI diagnostic thresholds for three of the four disorders were increased to make sure prevalence estimates based on the CIDI were conservative. The procedures used to implement these recalibrations are described in this paper.

CONCLUSIONS

The CIDI interviews used in the SNMHS generated valid but conservative diagnoses of common mental disorders in the Saudi population.

Development and psychometric evaluation of the Mandarin Chinese version of the Yale-Brown Obsessive-Compulsive Scale - Second Edition

Objective:

To examine the psychometric properties of the Chinese version of the Yale-Brown Obsessive Compulsive Scale – Second Edition (Y-BOCS-II).

Method:

A total of 86 adults with a primary diagnosis of obsessive-compulsive disorder (OCD), ranging in age from 15 to 78 years, participated in the study. Participants were administered the Y-BOCS-II by a trained clinician who also rated overall illness severity on two additional measures. Patients completed the Obsessive Compulsive Inventory-Revised and Depression Anxiety Stress Scale-21.

Results:

Results indicated high internal consistency and fair 1-week test retest reliability. The Y-BOCS-II scales correlated strongly with clinician-rated obsessive-compulsive severity and modestly with self-reported obsessive-compulsive symptom frequency and distress. The relationship between Y-BOCS-II total score and depressive and anxiety symptoms was strong, which may reflect high rates of comorbid conditions in this sample or the linkage between obsessive-compulsive symptom severity and distress. Factor analysis demonstrated a two-factor structure consisting of obsession and compulsion factors, with interference due to obsessions cross-loading.

Conclusions:

Overall, these results support the use of the Y-BOCS-II among individuals from China. Future study by an independent group is necessary to replicate these findings, as well as investigate interrater reliability and treatment sensitivity.