基于对中国患者的纵向研究验证一种简单的银屑病严重程度衡量方法。

Validation of a simple measure of psoriasis severity based on a longitudinal study of Chinese patients.

机构信息

Department of Dermatology, Xiangya Hospital, Central South University, Changsha, China, Hunan Engineering Research Center of Skin Health and Disease, Central South University, Changsha, China, Hunan Key Laboratory of Skin Cancer and Psoriasis, Central South University, Changsha, China, Department of Social Medicine and Health Management, Xiangya School of Public Health, Central South University, Changsha, China.

出版信息

Eur J Dermatol. 2020 Dec 1;30(6):674-679. doi: 10.1684/ejd.2020.3914.

DOI:10.1684/ejd.2020.3914

PMID:33459259

Abstract

BACKGROUND

The product of Physician Global Assessment (PGA) and Body Surface Area (BSA) (PGA × BSA) has been proposed as a simple and sensitive instrument for measuring psoriasis severity.

OBJECTIVES

To assess the simple measure, PGA × BSA, with respect to criterion validity, reproducibility, responsiveness, and interpretability among Chinese patients with psoriasis.

MATERIALS & METHODS: Assessments of psoriasis severity were performed by two dermatologists independently for the baseline survey and by one dermatologist during follow-up. Criterion validity and reproducibility were assessed using Spearman correlation coefficients (r). Responsiveness was assessed by comparing the percentage changes in PGA × BSA (PGA × ΔBSA [%]) between patients grouped by disease improvement. The receiver operating characteristic (ROC) curve was used to determine the threshold of PGA × ΔBSA for disease improvement, anchored by 50% and 75% reduction in Psoriasis Area Severity Index (PASI).

RESULTS

A total of 276 patients participated in the baseline survey, of whom 93 were followed. PGA × BSA highly correlated with PASI (r = 0.94), Simplified PASI (SPASI, r = 0.93), and Psoriasis Log-based Area and Severity Index (PLASI, r = 0.90) measured at baseline, indicating good criterion validity. The between-evaluator consistency of PGA × BSA was r = 0.95, indicating high reproducibility. PGA × ΔBSA highly correlated with both ΔPASI (r = 0.86) and ΔPLASI (r = 0.85), suggesting good responsiveness. The threshold of ΔPGA × BSA for disease improvement was 57% and 73%, as indicated by 50% and 75% reduction in PASI, respectively.

CONCLUSION

PGA × BSA demonstrates good biometric properties and may be used to measure the severity of psoriasis among Chinese patients.

摘要

背景

医师总体评估（PGA）和体表面积（BSA）的乘积（PGA×BSA）已被提议作为一种简单而敏感的工具来衡量银屑病的严重程度。

目的

评估中国银屑病患者 PGA×BSA 的简单测量方法在标准效度、可重复性、反应性和可解释性方面的表现。

材料和方法

两名皮肤科医生独立对基线调查进行银屑病严重程度评估，一名皮肤科医生在随访期间进行评估。使用 Spearman 相关系数（r）评估标准效度和可重复性。通过比较按疾病改善分组的患者 PGA×BSA（PGA×ΔBSA [%]）的百分比变化来评估反应性。使用受试者工作特征（ROC）曲线确定 PGA×ΔBSA 用于疾病改善的阈值，以 PASI 降低 50%和 75%为锚点。

结果

共有 276 名患者参加了基线调查，其中 93 名患者接受了随访。PGA×BSA 与 PASI（r=0.94）、简化 PASI（SPASI，r=0.93）和基于 psoriasis log 的面积和严重度指数（PLASI，r=0.90）高度相关，表明具有良好的标准效度。PGA×BSA 的两位评估者之间的一致性为 r=0.95，表明具有高度的可重复性。PGA×ΔBSA 与ΔPASI（r=0.86）和ΔPLASI（r=0.85）高度相关，表明具有良好的反应性。ΔPGA×BSA 用于疾病改善的阈值分别为 PASI 降低 50%和 75%所对应的 57%和 73%。