title: Validation of the UCLA Scleroderma Clinical Trial Consortium Gastrointestinal Tract Instrument 2.0 in English- and Chinese-speaking patients in a multi-ethnic Singapore systemic sclerosis cohort.
abstract: The aim of this study was to (1) translate the Gastrointestinal Tract Instrument (GIT) 2.0 from English to Chinese and (2) validate both versions in a multi-ethnic systemic sclerosis cohort in Singapore (SCORE). The English GIT2.0 was translated to Chinese using a standard forward-backward translation approach. Psychometric evaluation of the GIT2.0 included internal consistency reliability (using Cronbach's alpha), test-retest reliability (using intra-class correlation coefficient (ICC)), scale level factor analysis, and construct validity (using Spearman correlation) against the modified Scleroderma Health Assessment Questionnaire (S-HAQ) and the SF-36 v2. Most of the patients were females (88.6%) and Chinese (78.2%), with mean (SD) age of 51.0 (13.0) years and median disease duration of 4.5 years. We administered English (n = 146) and Chinese (n = 74) GIT2.0. The mean (SD) total GIT score was 0.29 (0.37). There was good internal consistency (Cronbach's alpha >0.70 for all subscales) and good test-retest reliability for the scale and all subscales (ICC 0.71-0.92) except for "diarrhoea" (ICC = 0.54). Our hypothesised a priori construct validity was supported by moderate correlations between the total GIT score and S-HAQ GI subscale (r = 0.446), and the social functioning subscale and SF36v2 role-social domain (r = 0.337), and weak-to-moderate correlation between the emotional subscale and SF-36v2 role-emotional (r = 0.295) and mental health (r = 0.298) domains and mental component summary (r = 0.356). Exploratory factor analysis of the seven subscales yielded a two-factor solution explaining 69.63% of the total variance. This study provides evidence for the reliability and validity of the English and Chinese GIT2.0 to be used in Singapore for research and routine practice.
authors.affiliation: Department of Rheumatology and Immunology, Singapore General Hospital, The Academia, Level 4, 20 College Road, Singapore, 169856, Singapore. andrea.low.h.l@singhealth.com.sg.|Duke-National University of Singapore, Singapore, Singapore. andrea.low.h.l@singhealth.com.sg.
authors.forename: Andrea Hsiu Ling
authors.initials: AHL
authors.lastname: Low
authors.affiliation: Medicine Academic Clinical Programme, Singapore General Hospital, Singapore, Singapore.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Xin
authors.affiliation: Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore, Singapore.
authors.forename: Weng Giap
authors.initials: WG
authors.lastname: Law
authors.affiliation: Division of Rheumatology, University Medicine Cluster, National University Health System, Singapore, Singapore.|Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Gim Gee
authors.initials: GG
authors.lastname: Teng
authors.affiliation: Division of Rheumatology, University Medicine Cluster, National University Health System, Singapore, Singapore.|Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Amelia
authors.initials: A
authors.lastname: Santosa
authors.affiliation: Division of Rheumatology, University Medicine Cluster, National University Health System, Singapore, Singapore.|Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Anita
authors.initials: A
authors.lastname: Lim
authors.affiliation: Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore, Singapore.
authors.forename: Grace
authors.initials: G
authors.lastname: Chan
authors.affiliation: Department of Rheumatology and Immunology, Singapore General Hospital, The Academia, Level 4, 20 College Road, Singapore, 169856, Singapore.|Duke-National University of Singapore, Singapore, Singapore.
authors.forename: Swee Cheng
authors.initials: SC
authors.lastname: Ng
authors.affiliation: Department of Rheumatology and Immunology, Singapore General Hospital, The Academia, Level 4, 20 College Road, Singapore, 169856, Singapore.|Duke-National University of Singapore, Singapore, Singapore.
authors.forename: Julian
authors.initials: J
authors.lastname: Thumboo
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D041981:Gastrointestinal Tract / Q000503:physiopathology*; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D012595:Scleroderma, Systemic / Q000175:diagnosis* / Q000503:physiopathology; D012720:Severity of Illness Index; D012846:Singapore; D014177:Translations
keywords: Gastrointestinal tract; Systemic sclerosis; Validation studies