Validation of the Psoriasis Symptom Inventory (PSI), a patient-reported outcome measure to assess psoriasis symptom severity. J Dermatolog Treat 2013 Oct;24(5):356-60
Date
10/25/2012Pubmed ID
23092173DOI
10.3109/09546634.2012.742950Scopus ID
2-s2.0-84883575731 (requires institutional sign-in at Scopus site) 53 CitationsAbstract
BACKGROUND: The objective of this study was to evaluate the measurement properties of the Psoriasis Symptom Inventory (PSI), an eight-item patient-reported outcome measure for assessing severity of plaque psoriasis symptoms.
METHODS: In this prospective, randomized study using data from adults with moderate-to-severe plaque psoriasis, patients completed the PSI, Dermatology Life Quality Index (DLQI), SF-36v2 Acute, and Patient Global Assessment (PtGA). PSI construct validity was assessed using Spearman rank correlations between PSI and DLQI and SF-36; test-retest reliability and sensitivity to change were evaluated using PtGA as an anchor. Daily 24-h and weekly 7-day PSI versions were evaluated.
RESULTS: Eight US sites enrolled 143 patients; 139 (97.2%) completed the study. All symptoms (itch, redness, scaling, burning, cracking, stinging, flaking, and pain) were reported across all response options (not at all severe, mild, moderate, severe, very severe). Test-retest reliability was acceptable (intraclass correlation coefficients range = 0.70-0.80). A priori hypotheses of convergent and discriminant validity were confirmed by correlations of PSI with DLQI items and SF-36 domains. The PSI demonstrated good construct validity and was sensitive to within-subject change (p < 0.0001).
CONCLUSIONS: The PSI is brief, valid, reproducible, and responsive to change and has the potential to be a useful PRO measure in psoriasis clinical trials.
Author List
Bushnell DM, Martin ML, McCarrier K, Gordon K, Chiou CF, Huang X, Ortmeier B, Kricorian GAuthor
Kenneth Brian Gordon MD Chair, Professor in the Dermatology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdultAged
Aged, 80 and over
Female
Humans
Male
Middle Aged
Prospective Studies
Psoriasis
Self Report
Severity of Illness Index
Young Adult
