UOC Reumatologia e Malattie Autoinfiammatorie, IRCCS Istituto Giannina Gaslini, Genova, Italy
UOC Reumatologia e Malattie Autoinfiammatorie, IRCCS Istituto Giannina Gaslini, Genova, Italy.
RMD Open. 2024 Feb 2;10(1):e003093. doi: 10.1136/rmdopen-2023-003093.
To develop and validate the cut-offs in the Juvenile DermatoMyositis Activity Index (JDMAI) to distinguish the states of inactive disease (ID), low disease activity (LDA), moderate disease activity (MDA) and high disease activity (HDA) in children with juvenile dermatomyositis (JDM).
For cut-off definition, data from 139 patients included in a randomised clinical trial were used. Among the six versions of the JDMAI, JDMA1 (score range 0-40) and JDMAI2 (score range 0-39) were selected. Optimal cut-offs were determined against external criteria by calculating different percentiles of score distribution and through receiver operating characteristic curve analysis. External criteria included the modified Pediatric Rheumatology International Trials Organization (PRINTO) criteria for clinically ID in JDM (for ID) and PRINTO levels of improvement in the clinical trial (for LDA and HDA). MDA cut-offs were set at the score interval between LDA and HDA cut-offs. Cut-off validation was conducted by assessing construct and discriminative ability in two cohorts including a total of 488 JDM patients.
The calculated JDMAI1 cut-offs were ≤2.4 for ID, ≤6.6 for LDA, 6.7-11 for MDA and >11 for HDA. The calculated JDMAI2 cut-offs were ≤5.2 for ID, ≤8.5 for LDA, 8.6-11.3 for MDA and >11.3 for HDA. The cut-offs discriminated strongly among disease activity states defined subjectively by caring physicians and parents, parents' satisfaction or non-satisfaction with illness outcome, levels of pain, fatigue, physical functional impairment and physical well-being.
Both JDMAI1 and JDMAI2 cut-offs revealed good metrologic properties in validation analyses and are, therefore, suited for application in clinical practice and research.
制定并验证青少年皮肌炎活动指数（JDMAI）的切点，以区分儿童皮肌炎（JDM）患者无疾病活动状态（ID）、低疾病活动状态（LDA）、中度疾病活动状态（MDA）和高疾病活动状态（HDA）。
在一项随机临床试验中，我们使用了 139 例患者的数据进行切点定义。在 JDMAI 的六个版本中，选择了 JDMA1（评分范围 0-40）和 JDMAI2（评分范围 0-39）。通过计算不同的分数分布百分位数和接受者操作特征曲线分析，根据外部标准确定最佳切点。外部标准包括改良的儿科风湿病国际试验组织（PRINTO）JDM 的临床 ID 标准（用于 ID）和临床试验中的 PRINTO 改善水平（用于 LDA 和 HDA）。MDA 切点设定在 LDA 和 HDA 切点之间的评分区间。通过评估两个共包括 488 例 JDM 患者的队列中的结构和鉴别能力来验证切点。
计算得出的 JDMAI1 切点为 ID 时≤2.4，LDA 时≤6.6，MDA 时 6.7-11，HDA 时>11。计算得出的 JDMAI2 切点为 ID 时≤5.2，LDA 时≤8.5，MDA 时 8.6-11.3，HDA 时>11.3。这些切点可在主观定义的疾病活动状态（由照顾医生和家长定义）、家长对疾病结局的满意度或不满意、疼痛、疲劳、身体功能障碍和身体舒适度等方面进行强烈区分。
JDMAI1 和 JDMAI2 切点在验证分析中均显示出良好的计量学特性，因此适用于临床实践和研究。
