Inter- and Intra-Observer Reliability of Modified Rodnan Skin Score Assessment in Thai Systemic Sclerosis Patients: A Validation for Multicenter Scleroderma Cohort Study.

Background: Assessment of the severity of skin tightness by the modified Rodnan skin score (mRSS) for systemic sclerosis (SSc) has been found feasible, valid, and reliable. Despite being a major clinical outcome, it has not yet been validated by Scleroderma Research Group.

Objective: To (a) determine the inter-observer variability vis-à-vis mRSS assessment by members ofthe Scleroderma Research Group before and after mRSS-assessment training by an experienced rheumatologist and (b) determine intra-observer variability.