Department of Dermatology, University of Pennsylvania, Philadelphia, 19104, USA.
Br J Dermatol. 2011 Mar;164(3):602-9. doi: 10.1111/j.1365-2133.2010.10134.x. Epub 2011 Feb 3.
Psoriasis is a common disease frequently studied in large databases. To date the validity of psoriasis information has not been established in The Health Improvement Network (THIN).
To investigate the validity of THIN for identifying patients with psoriasis and to determine if the database can be used to determine the natural history of the disease.
First, we conducted a cross-sectional study to determine if psoriasis prevalence in THIN is similar to expected. Second, we created a cohort of 4900 patients, aged 45-64 years, with a psoriasis diagnostic Read Code and surveyed their general practitioners (GPs) to confirm the diagnosis clinically. Third, we created models to determine if psoriasis descriptors (extent, severity, duration and dermatologist confirmation) could be accurately captured from database records.
Psoriasis prevalence was 1·9%, and showed the characteristic age distribution expected. GP questionnaires were received for 4634 of 4900 cohort patients (95% response rate), and psoriasis diagnoses were confirmed in 90% of patients. Duration of disease in the database showed substantial agreement with physician query (κ = 0·69). GPs confirmed that the psoriasis diagnosis was corroborated by a dermatologist in 91% of patients whose database records contained a dermatology referral code associated with a psoriasis code. We achieved good discrimination between patients with and without extensive disease based on the number of psoriasis codes received per year (area under curve = 0·8).
THIN is a valid data resource for studying psoriasis and can be used to identify characteristics of the disease such as duration and confirmation by a dermatologist.
银屑病是一种在大型数据库中经常研究的常见疾病。迄今为止，尚未在健康改进网络（THIN）中验证银屑病信息的有效性。
调查 THIN 识别银屑病患者的有效性，并确定该数据库是否可用于确定疾病的自然史。
首先，我们进行了一项横断面研究，以确定 THIN 中的银屑病患病率是否与预期相符。其次，我们创建了一个由 4900 名年龄在 45-64 岁之间的患者组成的队列，这些患者的银屑病诊断记录代码为 Read Code，并调查他们的全科医生（GP）以临床确认诊断。第三，我们创建了模型，以确定是否可以从数据库记录中准确捕获银屑病描述符（范围、严重程度、持续时间和皮肤科医生确认）。
银屑病的患病率为 1.9%，并显示出预期的典型年龄分布。我们收到了 4900 名队列患者中 4634 名（95%的响应率）的 GP 问卷，并且在 90%的患者中确认了银屑病诊断。数据库中疾病的持续时间与医生查询具有显著一致性（κ=0.69）。在数据库记录中包含与银屑病代码相关的皮肤科转诊代码的患者中，91%的患者其 GP 确认了银屑病诊断得到了皮肤科医生的证实。我们根据每年收到的银屑病代码数量，在有和没有广泛疾病的患者之间实现了良好的区分（曲线下面积=0.8）。
THIN 是研究银屑病的有效数据资源，可用于识别疾病的特征，如持续时间和皮肤科医生的确认。
