Validity and reliability of patient reported outcomes used in Psoriasis: results from two randomized clinical trials

Table 5 Correlations Among Change Scores for PSA Frequency and Severity Scores, DLQI Scores and NPF Itch Scores with Change Scores on Clinical Measures and with the Physician's Global Assessment of Change (PGA) at Week 12

	STUDY A			STUDY B
Difference Scores: Baseline to Week 12	Clinical Measure			Clinical Measure
Scale/Subscale	PASI	OLS	PGA ¹	PASI	OLS	PGA ¹
Total Score PSA Frequency – 8 item scale	0.49	0.47	0.54	0.53	0.54	0.57
Total Score PSA Frequency – 7 item scale	0.46	0.44	0.51	0.51	0.51	0.54
Total Score PSA Severity – 8 item scale	0.50	0.49	0.55	0.52	0.53	0.57
Total Score PSA Severity – 7 item scale	0.47	0.47	0.53	0.51	0.51	0.55
DLQI Total Scale	0.47	0.43	0.46	0.54	0.46	0.53
DLQI Symptoms and Feelings Subscale	0.53	0.48	0.52	0.52	0.51	0.56
DLQI Daily Activities Subscale	0.38	0.37	0.40	0.44	0.35	0.43
DLQI Leisure Subscale	0.34	0.29	0.33	0.36	0.27	0.31
DLQI Work and School Subscale	0.18	0.16	0.20	0.27	0.26	0.30
DLQI Personal Relationship Subscale	0.23	0.20	0.25	0.32	0.29	0.33
DLQI Treatment Subscale	0.38	0.32	0.35	0.44	0.36	0.38
NPF Itch Scale	n/a	n/a	n/a	0.46	0.44	0.52
VAS Itch Scale	0.50	0.47	0.51	n/a	n/a	n/a

All correlations are significant at p < 0.001 ¹ PGA is assessed only at end of treatment

ISSN: 1477-7525