Exploring content and psychometric validity of newly developed assessment tools for itch and skin pain in atopic dermatitis

Journal of Patient-Reported Outcomes

Table 3 Results of Psychometric Analysis of Real-World Daily eDiary Data

Parameter	Itch NRS^[a]	Skin Pain NRS^[a]
Test-retest reliability^[b] (n = 31)
Week 1 to Week 2 Average	0.95	0.97
Day 7 to Day 14	0.94	0.91
Concurrent validity^[c]
POEM (Week 1; n = 74)	0.80	0.75
POEM (Week 2; n = 66)	0.84	0.77
PGIS (Week 1; n = 55)	0.72	0.68
PGIS (Week 2; n = 42)	0.74	0.65
DLQI Summary Score (Adult population; n = 33–53)	0.59–0.74	0.57–0.73
CDLQI Summary Score (Adolescent population; n = 9–19)	0.76–0.89	0.77–0.91
Responsiveness^[d]
Week 1 to Week 2 Average	p = 0.02	p = 0.003
Decline	ES = 1.21 (n = 5)	ES = 1.09 (n = 5)
No Decline	ES = 0.41 (n = 24)	ES = 0.34 (n = 39)
Day 7 to Day 14	p = 0.25	p = 0.42
Decline	ES = 0.40 (n = 5)	ES = 0.24 (n = 5)
No Decline	ES = 0.08 (n = 24)	ES = 0.04 (n = 24)

Abbreviations: CDLQI Children’s Dermatology Life Quality Index, DLQI Dermatology Life Quality Index, NRS Numeric rating scale, PGIS Patient Global Impression of Severity, POEM Patient Oriented Eczema Measure, ES Effect size
^[a]The NRS scales ranged from 0 to 10
^[b]Test-retest calculation assessed score changes from Day 7 and Day 14 and the Week 1 to Week 2 average in patients who showed a 0- or 1-point change on the PGIS scale
^[c]Correlations performed on Day 1, 7, 14, and the Week 1 to Week 2 average except for PGIS, which was only collected at Day 7 and 14
^[d]p-value from test for difference in mean score change of participants who scored above and below 4 on the PGIC between Weeks 1 and 2 and Day 7 and Day 14