Rheumatology Department, Coimbra University Hospital, Coimbra, Portugal.
Ann Rheum Dis. 2011 Jan;70(1):47-53. doi: 10.1136/ard.2010.138594. Epub 2010 Nov 10.
The Ankylosing Spondylitis Disease Activity Score (ASDAS) is a new composite index to assess disease activity in ankylosing spondylitis (AS). It fulfils important aspects of truth, feasibility and discrimination. Criteria for disease activity states and improvement scores are important for use in clinical practice, observational studies and clinical trials and so far have not been developed for the ASDAS.
To determine clinically relevant cut-off values for disease activity states and improvement scores using the ASDAS.
For the selection of cut-offs data from the Norwegian disease modifying antirheumatic drug (NOR-DMARD) registry, a cohort of patients with AS starting conventional or biological DMARDs, were used. Receiver operating characteristic analysis against several external criteria was performed and several approaches to determine the optimal cut-offs used. The final choice was made on clinical and statistical grounds, after debate and voting by Assessment of SpondyloArthritis international Society members. Crossvalidation was performed in NOR-DMARD and in Ankylosing Spondylitis Study for the Evaluation of Recombinant Infliximab Therapy, a database of patients with AS participating in a randomised placebo-controlled trial with a tumour necrosis factor blocker.
Four disease activity states were chosen by consensus: inactive disease, moderate, high and very high disease activity. The three cut-offs selected to separate these states were: 1.3, 2.1 and 3.5 units. Selected cut-offs for improvement were: change ≥1.1 units for clinically important improvement and change ≥2.0 units for major improvement. Results of the crossvalidation strongly supported the cut-offs.
Cut-off values for disease activity states and improvement using the ASDAS have been developed. They proved to have external validity and a good performance compared to existing criteria.
强直性脊柱炎疾病活动度评分（ASDAS）是一种新的综合指数，用于评估强直性脊柱炎（AS）的疾病活动度。它满足了真实性、可行性和区分性的重要方面。疾病活动状态和改善评分的标准对于临床实践、观察性研究和临床试验非常重要，但迄今为止尚未为 ASDAS 制定。
使用 ASDAS 确定疾病活动状态和改善评分的临床相关切点值。
为了选择切点值，使用了挪威疾病修饰抗风湿药物（NOR-DMARD）登记处的患者数据，这些患者患有开始使用传统或生物 DMARD 的 AS。对几种外部标准进行了接收者操作特征分析，并使用了几种方法来确定最佳切点值。最终选择是基于临床和统计学依据，经过评估 SpondyloArthritis 国际学会成员的辩论和投票后做出的。交叉验证在 NOR-DMARD 和强直性脊柱炎研究中进行，用于评估重组英夫利昔单抗治疗的疗效，这是一个数据库，其中包含参加随机安慰剂对照试验的 AS 患者，该试验使用肿瘤坏死因子阻滞剂。
通过共识选择了四种疾病活动状态：无疾病活动、中度、高度和极高疾病活动。选择了三个切点来区分这些状态：1.3、2.1 和 3.5 个单位。选择的改善切点为：临床重要改善的变化≥1.1 个单位，主要改善的变化≥2.0 个单位。交叉验证的结果强烈支持这些切点值。
已经开发了使用 ASDAS 的疾病活动状态和改善的切点值。它们被证明具有外部有效性和与现有标准相比良好的性能。
