Sampogna F, Linder D, Romano G V, Gualberti G, Merolla R, di Luzio Paparatti U
Health Services Research Unit, Istituto Dermopatico dell'Immacolata (IDI)-IRCCS, Rome, Italy.
J Eur Acad Dermatol Venereol. 2015 Apr;29(4):725-31. doi: 10.1111/jdv.12668. Epub 2014 Sep 17.
The Psodisk is a 10-item visual instrument, aimed at measuring the burden of psoriasis on patients.
To validate the Psodisk in a large sample of patients with psoriasis, and to define categories for the interpretation of the scores.
Data were collected in 21 dermatological centres. The Psodisk was administered at baseline (t0), after 2 or 3 days (t1) and about 3 months (t2) after baseline, and data were used to assess validity and reliability of the instrument. The cut-off scores were determined using the perception of the severity of the disease by the patient as anchor point.
The evaluable population consisted of 320 patients at baseline, with a mean Psodisk score of 36.9. The concurrent validity of the instrument was confirmed by the high correlation with Skindex-29 and DLQI. Factor analyses selected a single factor, which alone explained almost 60% of the variance. Cronbach's coefficient alpha was 0.927, suggesting a good reliability. Test-retest reliability was verified by a Pearson's correlation coefficient between the Psodisk scores at baseline and t1 of 0.924. Five categories of disease burden were defined: 1. minimal (<9); 2. mild (9-15); 3. moderate (16-30); 4. marked (31-50); 5. severe (>50).
The Psodisk showed good psychometric properties. The definition of the cut-off scores will be useful to evaluate the burden of psoriasis on patients.
Psodisk是一种包含10个项目的视觉工具，旨在测量银屑病对患者的负担。
在大量银屑病患者样本中验证Psodisk，并定义分数解释的类别。
在21个皮肤科中心收集数据。在基线时（t0）、基线后2或3天（t1）以及基线后约3个月（t2）使用Psodisk进行评估，数据用于评估该工具的有效性和可靠性。以患者对疾病严重程度的感知为锚点确定临界分数。
基线时可评估人群包括320名患者，Psodisk平均得分为36.9。该工具的同时效度通过与Skindex-29和DLQI的高度相关性得到证实。因子分析选择了一个单一因子，该因子单独解释了近60%的方差。Cronbach's系数α为0.927，表明可靠性良好。重测信度通过基线时和t1时Psodisk分数之间的Pearson相关系数0.924得到验证。定义了五类疾病负担：1. 极小（<9）；2. 轻度（9 - 15）；3. 中度（16 - 30）；4. 显著（31 - 50）；5. 重度（>50）。
Psodisk显示出良好的心理测量特性。临界分数的定义将有助于评估银屑病对患者的负担。
