Xie Wenhui, Li Guangtao, Huang Hong, Zhang Zhuoli
Department of Rheumatology and Clinical Immunology, Peking University First Hospital, No. 8, Xishiku Street, West District, Beijing, 100034, China.
Rheumatol Ther. 2021 Mar;8(1):289-301. doi: 10.1007/s40744-020-00270-z. Epub 2020 Dec 23.
The aim of this work is to propose Boolean-defined low disease activity (LDA) and to test its utility in rheumatoid arthritis (RA).
We used data from a longitudinal academic clinical database of RA in Peking University First Hospital over a decade. The initial proposal of Boolean-defined LDA was proposed with ascending thresholds from 2 to 5 in steps of 1 (referred to as Boolean-LDA2/3/4/5). Agreement and residual swollen joint count (SJC) pattern with the index-based [Simplified Disease Activity Index (SDAI) and Clinical Disease Activity Index (CDAI)] LDA was analyzed. To confirm discovery, we randomly classified RA patients in a 3:2 ratio into either analysis cohort or validation cohort.
In total, 4881 visits of 672 patients were included in the analysis cohort. Of these visits, the frequencies of achieving LDA were 71.9% (SDAI), 73.6% (CDAI), 52.8% (Boolean-LDA2), 65.2% (Boolean-LDA3), 73.5% (Boolean-LDA4), and 80.7% (Boolean-LDA5). High consistency and similar SJC pattern with SDAI-LDA or CDAI-LDA were observed in Boolean-LDA3 (kappa = 0.796, 0.771). Further analysis found meeting SDAI-LDA but not Boolean-LDA3 was largely attributable to higher patient's global assessment (PGA) scores (62.9%). In further modification of Boolean-LDA3, better agreement with SDAI-LDA or CDAI-LDA was reached when exclusively increasing PGA cutoffs to 4.0, 4.5 or replacing PGA by evaluator's global assessment (EGA) with cutoff to 3.0. These findings were further replicated in randomly generated validation cohort of 449 patients with 3306 clinic visits.
Using cutoff of 3 to Boolean-LDA provides great clinical utility with index-based LDA, especially when exclusively increasing PGA cutoffs to 4.0, 4.5 or replacing PGA by EGA with cutoffs to 3.0. This may deserve being considered in clinical practice.
本研究旨在提出基于布尔运算定义的低疾病活动度（LDA）并测试其在类风湿关节炎（RA）中的效用。
我们使用了来自北京大学第一医院长达十年的RA纵向学术临床数据库的数据。基于布尔运算定义的LDA最初的提议是将阈值从2逐步提高到5，步长为1（称为布尔-LDA2/3/4/5）。分析了与基于指数的[简化疾病活动指数（SDAI）和临床疾病活动指数（CDAI）]低疾病活动度的一致性和残余肿胀关节计数（SJC）模式。为了验证研究结果，我们将RA患者以3:2的比例随机分为分析队列或验证队列。
分析队列共纳入了672例患者的4881次就诊。在这些就诊中，达到低疾病活动度的频率分别为71.9%（SDAI）、73.6%（CDAI）、52.8%（布尔-LDA2）、65.2%（布尔-LDA3）、73.5%（布尔-LDA4）和80.7%（布尔-LDA5）。在布尔-LDA3中观察到与SDAI-LDA或CDAI-LDA具有高度一致性和相似的SJC模式（kappa = 0.796，0.771）。进一步分析发现，达到SDAI-LDA但未达到布尔-LDA3在很大程度上归因于患者整体评估（PGA）得分较高（62.9%）。在对布尔-LDA3的进一步修改中，当仅将PGA临界值提高到4.0、4.5或将PGA替换为评估者整体评估（EGA）且临界值为3.0时，与SDAI-LDA或CDAI-LDA的一致性更好。这些发现进一步在449例患者的3306次临床就诊的随机生成验证队列中得到了重复。
对布尔-LDA使用临界值3具有基于指数的低疾病活动度的巨大临床效用，特别是当仅将PGA临界值提高到4.0、4.5或将PGA替换为临界值为3.0的EGA时。这在临床实践中可能值得考虑。
