Self-assessment of skin tightness severity by scleroderma patients

Skin tightness progression determines the severity and mortality of systemic sclerosis (SSc). The modified Rodnan skin score (mRSS) is a skin tightness assessment tool, albeit inter-physician variability is a limitation. Our objectives were to evaluate the correlation and agreement of skin tightness assessment between patient self-assessment and physician-assessment.

A descriptive study was conducted on the masked, self-assessments of mRSS (at week 0, 4 and 12) by 23 Thai adult SSc patients seen at Srinagarind Hospital, KhonKaen University, between March 2014 and February 2015. Correlation between the physician and patient assessments was estimated using Pearson's. The intra-class correlation coefficient (ICC) and limit of agreement by Bland-Altman were determined.

We included 23 SSc patients (female to male ratio being 1.1:1). All had the diffuse cutaneous SSc subset. The skin thickness assessment correlation was moderate at baseline (Pearson's r = 0.68) and improved to a good correlation at week 4 and 12 (r = 0.78 and 0.86, respectively). The ICC showed good agreement (0.761) at week 0 and increased to excellent at week 4 (0.846) and 12 (0.910). The patient self-assessment score was higher than the physician assessment, which slightly decreased over time: mean difference = 4.30 (95% LOA;-9.54 to 18.14) at week 0, then 3.78 (95% LOA,-10.20 to 17.77) at week 4, and 3.16 (95% LOA,-7.78 to 14.10) at week 12.

The respective modified Rodnan skin score assessment by patient versus the physician was highly correlated with a high level of agreement. Validation of generalized patient self-assessment needs to be confirmed.