Validity and reliability study of the Thai version of WHO Schedules for Clinical Assessment in Neuropsychiatry: Eating Disorders Section.

OBJECTIVE

To determine the validity and reliability of the Thai version of the WHO Schedules for Clinical Assessment in Neuropsychiatry (SCAN) Version 2.1, Eating Disorders Section

MATERIAL AND METHOD: The SCAN interview version 2.1 Eating Disorders Section (section 9) was translated into Thai. The content validity of the translation was verified by comparing the back-translation 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 in four regions (Suanprung Psychiatric Hospital, Jitavejkhonkaen Hospital, Srithanya Hospital and Suansaranrom Psychiatric Hospital, each place comprised 20 volunteers) for comprehensibility of the relatively technical language. Re-edition of the Thai version was made in accordance with suggestions from the field trial. The reliability study was done between October 2005 and September 2008 in which 30 persons (4 males; 26 females) were recruited. Fifteen persons (1 males and 14 females) were eating disorders patients (4 anorexia nervosa and 11 bulimia nervosa patients) and the other 15 (3 males and 12 females) were normal. The number of years of formal education varied widely and occupations were diverse. Subjects were interviewed using SCAN eating disorders section by a psychiatrist competent in using the Thai version of SCAN. The interviews were recorded on video so that the material could be re-rated.

RESULTS

Regarding validity of WHO SCAN eating disorders section, based on the response from Thai subjects and consultations with competent psychiatrists, the content validity was established. Regarding the reliability study, the time taken to interview an eating disorder patient averaged 23.80 +/- 5.15 minutes (range, 18.35-34.26) versus 17.27 +/- 4.05 minutes (range, 9.07-22.37) for a normal subject. The mean of inter-rater reliability (kappa) of the eating disorder section was 0.73, standard error (SE) = 0.02, 95% confident interval (CI = 0.68-0.77). Seventy-eight point five percent of the items in the section had a substantial kappa. The mean of intra-rater reliabilities was 0.76, SE = 0.03, 95% CI = 0.70-0.82. Sixty-eight point four percent and 31.58% of the items had a substantial and almost perfect kappa respectively.

CONCLUSION

The Thai version of the Eating Disorders Sections of SCAN version 2.1 proved to be a valid and reliable tool for assessing eating disorders among Thai speakers.