Psychometric validation of the Hand Disability in Systemic Sclerosis-Digital Ulcers (HDISS-DU®) patient-reported outcome instrument

Table 1 HDISS-DU score: test-retest reliability in stable patients

Definition of stable patients	Number	Mean HDISS-DU score (SD)			T value	p value	ICC [95% CI]
Definition of stable patients	Number	Baseline	Week 4	Difference (week 4 − baseline)	T value	p value	ICC [95% CI]
Patient-reported global change: ‘no change’ at week 4	170	2.83 (1.14)	2.84 (1.14)	0.01 (0.55)	0.33	0.7381	0.88 [0.85–0.91]
Physician-reported global change: ‘no change’ at week 4	151	2.79 (1.10)	2.82 (1.09)	0.03 (0.58)	0.60	0.5491	0.86 [0.81–0.89]
Patient-reported severity: identical score at baseline and week 4	178	2.80 (1.07)	2.84 (1.09)	0.04 (0.52)	1.02	0.3084	0.89 [0.85–0.91]
Physician-reported severity: identical score at baseline and week 4	273	2.92 (1.10)	2.91 (1.09)	− 0.01 (0.65)	− 0.18	0.8579	0.82 [0.78–0.86]

The reproducibility of HDISS-DU scores between baseline and week 4 was assessed in stable patients (defined in four different ways based on patient-reported and physician-reported global assessments) by ICCs and paired t tests
CI confidence interval, DU digital ulcer, HDISS-DU Hand Disability in Systemic Sclerosis-Digital Ulcers, ICC intraclass correlation coefficient, n number of participants, SD standard deviation

ISSN: 1478-6362