Self-reported skin severity and quality of life in systemic sclerosis: multicentre validation of PASTUL.

Objectives: The aim of this study was to validate the Patient self-Assessment of Skin Thickness in Upper Limb questionnaire (PASTUL) in systemic sclerosis (SSc) and assess impact of skin involvement on health-related quality of life (HRQoL).

Methods: Participants were included in four UK centres. PASTUL specifies a grading of skin at 8 sites corresponding to the modified Rodnan Skin Score (mRSS). Construct validity was assessed by comparing PASTUL scores with mRSS. HRQoL was evaluated with EQ5D5L and Leeds SSc HRQoL questionnaires. Additionally, correlation between PASTUL and Scleroderma Skin Patient reported Outcome (SSPRO) was explored. Follow-up was 12 months.

Results: In total, 196 participants were included, mean age was 56.4 years (SD 13.9), 80.6% female (n = 158), mean disease duration 11.9 years (SD 9.9), 110 (56.1%) had limited cutaneous (lcSSc) and 81 (41.3%) diffuse cutaneous SSc (dcSSc). PASTUL and upper limb mRSS were well correlated at baseline, 6 and 12 months (ICC = 0.67, 0.78 and 0.62, p< 0.001). Test-retest reliability was good (ICC = 0.83, p< 0.001). There was a stronger correlation between PASTUL and upper limb mRSS in dcSSc compared with lcSSc (0.69 vs 0.51, p< 0.001). In participants with early disease (< 4 years) PASTUL was moderately correlated with HRQoL (r = 0.53, p< 0.001), correlations were weaker in the whole group. Mean time to do the PASTUL self-assessment was 5.0 min (SD 3.7).

Conclusion: PASTUL is a feasible outcome tool that adds to assessments as SSPRO. Skin thickening is correlated with HRQoL, particularly in early disease.