Background/Purpose: Gastrointestinal tract (GIT) involvement occurs in approximately 95% of patients with systemic sclerosis (SSc). There is consensus in the Scleroderma Clinical Trials Consortium (SCTC) Working Group on the importance of validating outcome measures in SSc. The goal of this project was to evaluate patient reported outcome measures in the SSc-associated domain of gastroesophageal reflux disease (GERD) through instrument assessment of responsiveness to change.

Methods: Patients who fulfill 2013 revised ACR/EULAR criteria for SSc and who had (1) GERD symptoms for at least 3 of the past 7 days; and (2) a plan to initiate a change in GERD management were eligible.  At baseline, all patients completed GERD assessment questionnaires including:  the UCLA GIT 2.0, Quality of Life in Reflux and Dyspepsia (QoLRAD), and in English-speaking countries, the NIH Patient Reported Outcome Measurement Information System (PROMIS®) GI Symptoms Scale. Cronbach’s alpha was assessed for the GIT 2.0 and QoLRAD domains; an alpha >=0.70 is considered acceptable for group comparisons. Pearson correlation coefficients were interpreted as proposed by Cohen: 0.0- 0.10, no correlation; 0.10- 0.23, small correlation; 0.24- 0.36, medium correlation; >=0.37, large correlation.

Results: In this ongoing registry, 5 participating international sites have so far recruited 68 GERD patients who completed GIT 2.0 and QoLRAD, and 29 patients completed the NIH PROMIS GI Reflux scale.  The diagnosis of GERD was made by clinical symptoms in 67 patients, 3 of whom had their diagnosis confirmed by barium swallow, and two of whom had an endoscopy with evidence of esophagitis. The patient sample has a mean age of 54.9 years, mean disease duration of 10.5 years, and is 83% female. Cronbach’s alpha for GIT 2.0 was 0.83 and for QoLRAD domains ranged from 0.92-0.96. The mean scores for Reflux scales on GIT 2.0 (0.96) and NIH PROMIS (57.5) suggested moderate overall reflux symptoms. GIT 2.0 and PROMIS had large correlations with each other and QoLRAD domains (except PROMIS had medium correlation with emotional distress domain of QoLRAD).

Conclusion: This multi-center international prospective study of SSc-GERD suggests that current PROs (GIT 2.0, PROMIS, and QoLRAD) have acceptable reliability and have large correlations among each other (except for 1 domain for QoLRAD with PROMIS). This study highlights challenges for studying GERD in an international cohort, including the infrequent use of invasive studies for GERD diagnosis and the limitations in the availability of translated instruments.  Nonetheless, this study underscores the value of international collaboration supported by the SCTC.