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 (PASTUL) questionnaire in 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 eight sites corresponding to the modified Rodnan Skin Score (mRSS). Construct validity was assessed by comparing PASTUL scores with mRSS. HRQoL was evaluated with EuroQoL 5 dimension 5 levels (EQ5D5L) and Leeds SSc QoL 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 (s.d. 13.9), 80.6% female (n = 158), mean disease duration 11.9 years (s.d. 9.9), 110 (56.1%) had lcSSc and 81 (41.3%) dcSSc. PASTUL and upper limb mRSS were well correlated at baseline, 6 and 12 months [intraclass correlation coefficients (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 (s.d. 3.7). Conclusion: PASTUL is a feasible outcome tool that adds to assessments such as SSPRO. Skin thickening is correlated with HRQoL, particularly in early disease.