Validity and reliability study of the Thai version of WHO SCAN: somatoform and dissociative symptoms section.

ABSTRACT

OBJECTIVES: To determine the validity and reliability of the Thai version of the WHO Somatoform and Dissociative Symptoms Section of the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) Version 2.1 MATERIAL AND METHOD: The SCAN interview version 2.1 Somatoform and Dissociative Symptoms Section was translated into Thai. The content validity of the translation was verified by comparing a back-translation (to English) of the Thai version to the English original. Whenever inconsistencies were encountered, the Thai version was adapted so that it correctly conveyed the meaning of the original English version. The revised Thai version was then field-tested nationwide for the comprehensibility of the relatively technical language. Between October 2003 and August 2004, 30 persons were recruited for the reliability study (16 males; 14 females) Fifteen subjects had somatoform disorders and 15 were normal. The number of years of formal education varied widely and occupations were diverse. Subjects were interviewed by a psychiatrist competent in using the Thai version of SCAN. The interviews were recorded on video so that the material could be rerated. RESULTS: Based on the response from Thai subjects and consultations with competent psychiatrists, the content validity was established. The time taken to interview a somatoform patient averaged 57.1 +/- 12.1 minutes while it was 42.1 +/- 13.9 minutes for a normal subject. The inter-rater reliability (kappa) of the 113 Items were 0.81-1.0, 0.61-0.80 and 0. 00-0.20 in 49.6, 30.0 and 8.9 percent, respectively. Kappas could not be calculated for 11.5% of the Items. The intra-rater reliabilities were. 0.81-1.0, 0.61-0.80 and 0.00-0.20 in 54.9, 26.5 and 2.7 percent, respectively. Kappas could not be calculated for 15.9% of the Items. CONCLUSION: The Thai version of the Somatoform and Dissociative Symptoms Section of SCAN version 2.1 proved to be a valid and reliable tool for assessing somatoform and dissociative symptoms among Thai speakers.