Background/Purpose: Gastrointestinal tract (GIT) involvement occurs in approximately 90% of the patients with systemic sclerosis (SSc) and leads to a decrease in health-related quality of life. To identify and evaluate GIT involvement in patients with SSc, the University of California Scleroderma Clinical Trial Consortium Gastrointestinal Tract Instrument 2.0 (UCLA GIT 2.0) was developed. The UCLA GIT 2.0 consists of 34 items on 7-multi-item subscales. The total score averages 6 of 7 scales (excluding constipation) and ranges from 0 (no GIT problems) to 3 (most severe GIT problems) [1]. The aim of our study was to translate the UCLA GIT 2.0 from English into Dutch and validate the Dutch version.

Methods: First, the UCLA-GIT 2.0 questionnaire was translated according to international guidelines [2]. Secondly, the questionnaire was field-tested among 17 SSc patients. Then, in order to test internal consistency and validity, the final Dutch version was administered to SSc patients participating in a standardized, annual comprehensive medical assessment, compromising visits to health care professionals, laboratory and cardiopulmonary investigations, the SSc Health Assessment Questionnaire (SHAQ) and Short Form-36 (SF-36). The internal consistency was tested by computing Cronbach’s alpha. For convergent and construct validity, Pearson correlations were computed between the Dutch UCLA-GIT and the SF-36 and SHAQ. (r≤ 0.29 is considered a small correlation, r 0.30 -0.49 a moderate, and r ≥ 0.50 a strong correlation). To determine the reliability, the instrument was re-administered with an interval of two weeks to 27 of the patients, and the intraclass-correlation coefficient (ICC) was computed.

Results: Ninety-two patients were included. Patients were on average 53.8 (SD 15) years, mostly women (76%), Caucasian (82%) and 53% of the patients had limited cutaneous SSc. The median total UCLA GIT 2.0 score was 0.18 and a floor effect was seen (17% scored 0). Cronbach’s alpha was ≥0.73 for all scales, except diarrhea (alpha=0.42). The total GIT score was weakly or moderately associated with the SF-36 mental component summary scale (r=-0.247, p<0.05), the SF-36 physical component summary scale (r=‑0.348, p<0.01) and the SHAQ score (r=0.287, p<0.01). Correlations between the GIT subscale scores and the SF-36 subscale scores were strong with respect to the corresponding emotional wellbeing and social functioning scale (r=-0.515, p<0.01). The test-retest reliability was acceptable (ICC: 0.788).

Conclusion: The Dutch UCLA GIT 2.0 questionnaire showed good internal consistency, reliability and an acceptable construct validity according to comparisons with SF-36 and SHAQ. The Dutch translation will now be further validated with objective measures of GIT involvement.

References

1.    Khanna D, et al. Reliability and validity of the University of California, Los Angeles Scleroderma Clinical Trial Consortium Gastrointestinal Tract Instrument. Arthritis Rheum 2009;61:1257-63.

2.    Beaton, D.E., et al. Guidelines for the process of cross-cultural adaptation of self-report measures. Spine 2000;25:3186-91.