Points to consider for clinical trials of the gastrointestinal tract in systemic sclerosis

Abstract

The pathogenesis of gastrointestinal tract involvement in SSc is not fully understood. However, gastrointestinal signs and symptoms are very common. Trials to test therapies, with rare exceptions, should be double-blind, randomized trials with either active therapy or placebo as comparators. Trial duration will vary dependent on the anticipated therapy and should usually be 6-24 weeks long, although some motility trials may need to be 52 weeks. As in any well-controlled trial, inclusion and exclusion criteria should encourage relatively uniform patients with sufficiently active disease to discern response, importantly considering disease duration. Previous therapy, co-morbid conditions, potentially confounding and/or concomitant therapy should be considered. Outcome measures should include both objective/semi-objective and subjective measures, although validated measures are not frequent and design needs to consider using only validated measures. Unvalidated measures can be included to validate them for future use. A full analysis plan should be completed before study commencement, including the method to account for missing data.

Pelvic Floor Muscle Exercise and Physical Therapy May Improve Systemic Sclerosis-Associated Fecal Incontinence

“…During this process, defining outcome variables plays an important role in interpreting the results in line with scientific evidence. Therefore, outcome measures should be reviewed and the objective and validated variables, which evaluate gastrointestinal tract involvement and treatment efficacy, should be chosen [13][14][15]. Furthermore, intervention methods should be determined.…”

“…In particular, other gastrointestinal tract involvements other involvement, other than SSc-associated fecal incontinence should also be investigated through careful patient questioning and examination. Even though disease duration is one of the most important concerns in building the study population, any disease duration seems allowable to investigate the treatment approaches in SSc with gastrointestinal tract involvements [12,13]. Inclusion criteria might be developed in line with the preference of the authors.…”

“…After assessment of eligibility, randomization and allocation concealment should be performed based on the Consolidated Standards of Reporting Trials (CONSORT) statement [16]. The study duration should be designed, taking into consideration the long-term effect of the treatment [13]. Statistics plays an important role in designing, improving, analyzing, and presenting the study.…”