Reliability and validity of the Italian version of the UCLA Scleroderma Clinical Trial Consortium Gastrointestinal Tract Instrument in patients with systemic sclerosis

Objective. To test the acceptability, feasibility, reliability and validity of the Italian translated version of the UCLA Scleroderma Clinical Trial Consortium GIT (UCLA-SCTC GIT) 2.0. Gastrointestinal tract (GIT) involvement is frequent in systemic sclerosis (SSc). The UCLA-SCTC GIT 2.0 is a validated instrument for measuring the presence and impact of GIT symptoms in SSc patients. Methods. Acceptability and feasibility of the questionnaire were evaluated based on the input from the patients. Internal consistency was evaluated by Cronbach's alpha. External consistency was measured by comparing with the Short Form (SF)-36 and EQ-5D by Spearman's rho, meaningful if >= 0.30. Results. Sixty-two consecutive SSc patients (mean age 60.6) were recruited, 88.5% were female. The UCLA-SCTC GIT 2.0 was well accepted. Percentage of missing data in UCLA-SCTC GIT total score was 2 %. Internal consistency was acceptable (alpha >= 70) for all domains. Cronbach's alpha was >= 0.70 for all domains. UCLA-SCTC GIT 2.0 discriminated between patients with or without gastroesophageal reflux disease whether diagnosed clinically or by objective testing (p<0.01 for both). UCLA-SCTC GIT emotional well-being was correlated with the conceptually equivalent SF-36 mental health domains (correlation coefficient >0.35) and with the EQ-5D usual activities domain (0.38), thus reflecting the impact on everyday activities. The distention/bloating domain strongly correlated with the EQ-5D anxiety/depression domain (0.51) and reflux domain with role emotional of SF-36 (0.44). Conclusion. This is the first validation study of the Italian version of UCLA-SCTC GIT 2.0. Our data support its feasibility, reliability, and validity in Italian SSc patients.