Viswanathan Hema N, Mutebi Alex, Milmont Cassandra E, Gordon Kenneth, Wilson Hilary, Zhang Hao, Klekotka Paul A, Revicki Dennis A, Augustin Matthias, Kricorian Gregory, Nirula Ajay, Strober Bruce
Amgen Inc., Thousand Oaks, CA, USA.
Amgen Inc., Thousand Oaks, CA, USA.
Value Health. 2017 Sep;20(8):1174-1179. doi: 10.1016/j.jval.2016.11.020. Epub 2017 Jun 16.
The Psoriasis Symptom Inventory (PSI) is a patient-reported outcome instrument that measures the severity of psoriasis signs and symptoms. This study evaluated measurement properties of the PSI in patients with moderate to severe plaque psoriasis.
This secondary analysis used pooled data from a phase 3 brodalumab clinical trial (AMAGINE-1). Outcome measures included the PSI, Psoriasis Area and Severity Index (PASI), static Physician's Global Assessment (sPGA), psoriasis-affected body surface area, 36-item Short-Form Health Survey version 2, and the Dermatology Life Quality Index (DLQI). The PSI was evaluated for dimensionality, item performance, reliability (internal consistency and test-retest), construct validity, ability to detect change, and agreement between PSI response and response measures based on the PASI, sPGA, and DLQI.
Results supported unidimensionality, good item fit, ordered responses, and PSI scoring. The PSI demonstrated reliability: baseline Cronbach's alpha ≥ 0.92 and intraclass correlation coefficients ≥ 0.95. Correlations between PSI total score and DLQI item 1 (r = 0.86), DLQI symptoms and feelings (r = 0.87), and 36-item Short-Form Health Survey version 2 bodily pain (r = -0.61) supported convergent validity. PSI scores differed significantly (P < 0.001) among severity groups based on the PASI (< 12/≥ 12), sPGA (0-1/2-3/4-5), body surface area (< 5%/5%-10%/> 10%), and DLQI (≤ 5/> 5) at weeks 8 and 12. At week 12, the PSI detected significant changes in severity based on PASI responses (< 50/50- < 75/≥ 75) and sPGA (0-1/≥ 2), and showed good agreement (k ≥ 0.66) between PSI response and PASI, sPGA, and DLQI responses.
The PSI demonstrated excellent validity, reliability, and ability to detect change in the severity of psoriasis signs and symptoms.
银屑病症状量表（PSI）是一种患者报告结局工具，用于测量银屑病体征和症状的严重程度。本研究评估了PSI在中度至重度斑块状银屑病患者中的测量特性。
本二次分析使用了一项3期布罗达单抗临床试验（AMAGINE-1）的汇总数据。结局指标包括PSI、银屑病面积和严重程度指数（PASI）、静态医生整体评估（sPGA）、银屑病累及的体表面积、36项简明健康调查问卷第2版以及皮肤病生活质量指数（DLQI）。对PSI进行了维度分析、条目性能评估、信度分析（内部一致性和重测信度）、结构效度分析、检测变化的能力分析以及基于PASI、sPGA和DLQI的PSI反应与反应指标之间的一致性分析。
结果支持单维度性、良好的条目拟合、有序反应和PSI评分。PSI显示出信度：基线Cronbach's α≥0.92，组内相关系数≥0.95。PSI总分与DLQI第1项（r = 0.86）、DLQI症状与感受（r = 0.87）以及36项简明健康调查问卷第2版身体疼痛（r = -0.61）之间的相关性支持了收敛效度。在第8周和第12周时，基于PASI（<12/≥12）、sPGA（0 - 1/2 - 3/4 - 5）、体表面积（<5%/5% - 10%/>10%）和DLQI（≤5/>5）的严重程度组间，PSI评分存在显著差异（P < 0.001）。在第12周时，PSI根据PASI反应（<50/50 - <75/≥75）和sPGA（0 - 1/≥2）检测到严重程度的显著变化，并且在PSI反应与PASI、sPGA和DLQI反应之间显示出良好的一致性（k≥0.66）。
PSI在检测银屑病体征和症状严重程度变化方面显示出优异的效度、信度和能力。
