Reliability and validity of the Thai version of the Yale–Brown Obsessive Compulsive Scale – Second Edition in clinical samples

Abstract

Purpose The Yale–Brown Obsessive Compulsive Scale (Y-BOCS) is regarded as the most acceptable tool for measuring obsessive–compulsive disorder symptom severity. Recently, the Yale–Brown Obsessive Compulsive Scale – Second Edition (Y-BOCS-II) was developed for better measurement. The study reported here aimed to evaluate the psychometric properties of the Thai version of the Yale–Brown Obsessive Compulsive Scale – Second Edition (Y-BOCS-II-T). Patients and methods The original version of the Y-BOCS-II was translated into Thai, which involved forward translation, synthesis of the translation, and back translation. Modification and cross-cultural adaptation were completed accordingly. The developed Y-BOCS-II-T, together with the Hamilton Rating Scale for Depression, was administered to 41 patients who had a primary diagnosis of obsessive–compulsive disorder. The patients then completed the Pictorial Thai Quality of Life instrument and Patient Health Questionnaire. Lastly, the Global Assessment of Functioning (GAF) and the Clinical Global Impression – Severity Scale (CGI-S) of all patients were blindly rated by another experienced psychiatrist who was not the interviewer. Results The mean total score of the Yale–Brown Obsessive Compulsive Scale – Second Edition – Severity Scale (Y-BOCS-II-SS) and the Yale–Brown Obsessive Compulsive Scale – Second Edition – Symptom Checklist (Y-BOCS-II-SC) were 18.44 (standard deviation =10.51) and 15.85 (standard deviation =9.58), respectively. The Y-BOCS-II-T had satisfactory internal consistency (Cronbach’s alpha =0.94 for the Severity Scale, and Kuder–Richardson Formula 20 =0.90 for the Symptom Checklist). Inter-rater reliability was excellent for both the Y-BOCS-II-SS and Y-BOCS-II-SC. Factor analysis of Y-BOCS-II-SS items revealed a two-factor component associated with obsession and compulsion. The Y-BOCS-II-SS correlated highly with the CGI-S and GAF ( r =0.75 and −0.76, respectively), but the Y-BOCS-II-SC correlated moderately ( r =0.42 for CGI-S; r =−0.39 for GAF). The Y-BOCS-II-SS and Y-BOCS-II-SC slightly to moderately correlated with the Hamilton Rating Scale for Depression, Patient Health Questionnaire, and Pictorial Thai Quality of Life, which might indicate the comorbidity depression and its effect on quality of life. Conclusion The Y-BOCS-II-T is a psychometrically reliable and valid measure for the assessment of both severity and characteristics of obsessive–compulsive symptoms in Thai clinical samples.

Evidence-Based Assessment of Obsessive–Compulsive Disorder

“…Additionally, it shows good convergence with other clinician-rated measures of OCD severity, and good discriminant validity from measures of worry and impulsivity. Discriminant validity from depression is fair 44,47–49. The Y-BOCS-II shows preliminary support for treatment sensitivity in a case report, with further examination in a large treatment sample needed 50,51.…”

“…Research suggests good to excellent internal consistency, excellent interrater reliability, and good short-term test–retest reliability 44,47–49. Additionally, it shows good convergence with other clinician-rated measures of OCD severity, and good discriminant validity from measures of worry and impulsivity.…”

“…Despite these considerable improvements, the Y-BOCS-II still has mixed support for its proposed factor structure. For example, although the authors of the Y-BOCS-II propose a two-factor structure of obsessions and compulsions, one study identified a two-factor structure comprising symptom severity and interference from symptoms 44,47,48…”

Reliability and Validity of the Thai Version of the Florida Obsessive‐Compulsive Inventory

“…Four interviewers, two psychiatrists and two psychiatric nurses, were adequately trained to use the Thai version of YBOCS-II and HAM-D by attending didactic seminars, observing a VDO of patients being interviewed, practicing to administer the measures and discussing the discrepancies between raters. Our interrater reliability was 0.97 for the HAM-D, and 0.99 for the YBOCS-II [ 14 ].…”

“…It is considered that the FOCI would be suitable for many countries in which mental health care service problems arise from the disparity between high number of patients and small number of psychiatrists, especially Thailand [ 13 ]. Although the Thai version of YBOCS-Second Edition is used as a measurement tool for OCD [ 14 ] in Thailand, it remains a clinician-rated and time-consuming measure. Therefore, this study aimed to evaluate the reliability and validity of the Thai Version of the Florida Obsessive-Compulsive Inventory (FOCI-T) to assess symptoms and severity of the OCD in clinical samples.…”