Table 4.

Known-groups validity of WI-NRS vs. other measures at baseline

Comparator measure	N	Mean WI-NRS score (SD)	T-value	F-value	P-value
Phase 2 cohort
Self-categorization of pruritus disease severity	174		− 2.16	–	0.0324
Profile B (moderate)	123	5.8 (1.74)
Profile C (severe)	51	6.5 (2.08)
PGI-S	171		–	6.30	< 0.0001
None	1	4.00 (−)
Mild	8	4.66 (1.34)
Moderate	74	5.87 (1.64)
Severe	74	5.96 (1.88)
Very severe	14	8.04 (1.90)
Skindex-10 total score	174		–	8.18	< 0.0001
≤ 25th percentile (best)	45	5.46 (1.81)
> 25th to ≤ 50th percentile	44	5.34 (1.71)
> 50th to ≤ 75th percentile	46	6.40 (1.59)
> 75th percentile (worst)	39	6.97 (1.93)
5-D Itch total score	174		–	5.96	0.0007
≤ 25th percentile (least itch)	44	5.16 (1.79)
> 25th to ≤ 50th percentile	51	5.87 (1.54)
> 50th to ≤ 75th percentile	41	6.49 (1.90)
> 75th percentile (worst itch)	38	6.68 (1.96)
MOS Sleep Problem Index II at week 1	174		–	2.08	0.1049
≤ 25th percentile (worst sleep)	46	5.71 (2.04)
> 25th to ≤ 50th percentile	42	5.66 (1.74)
> 50th to ≤ 75th percentile	44	6.51 (1.45)
> 75th percentile (best sleep)	42	6.18 (2.09)
Phase 3 cohort
5-D Itch total score	848	–	–	128.80	< 0.0001
≤ 25th percentile (best)	220	6.25 (1.12)
> 25th to ≤ 50th percentile	273	6.80 (1.23)
> 50th to ≤ 75th percentile	154	7.55 (1.20)
> 75th percentile (worst)	201	8.40 (1.21)
Skindex-10 total score	848	–	–	63.51	< 0.0001
≤ 25th percentile (least itch)	218	6.30 (1.20)
> 25th to ≤ 50th percentile	225	7.10 (1.41)
> 50th to ≤ 75th percentile	206	7.37 (1.23)
> 75th percentile (worst itch)	199	8.02 (1.34)

Differences in weekly mean WI-NRS scores by known groups were evaluated by linear model ANOVA or t-test

MOS, Medical Outcomes Study; PGI-S, Patient Global Impression of Worst Itch Severity; SD, standard deviation; WI-NRS, Worst Itching Intensity Numerical Rating Scale