Department of Rheumatology, All India Institute of Medical Sciences, New Delhi, India.
Department of Statistics, Aliah University, Kolkata, India.
Int J Rheum Dis. 2024 Nov;27(11):e15418. doi: 10.1111/1756-185X.15418.
To estimate objective cut-off values for Bath ankylosing Spondylitis Disease Activity Index (BASDAI) corresponding to Ankylosing Spondylitis Disease Activity Score with CRP (ASDAS) cut-off values (1.3, 2.1, and 3.5), and for interval changes (ΔBASDAI) corresponding to ΔASDAS (1.1 and 2).
In this multicentric study, adult patients with active axial spondyloarthritis (axSpA) treated with either tofacitinib 5 mg twice daily or adalimumab 40 mg subcutaneously fortnightly were recruited. Available paired data on BASDAI and ASDAS and paired interval change of these parameters (taken at least 3-months apart) were analyzed. Cut-off values for BASDAI were determined from a multinomial logistic regression and that for ΔBASDAI were determined with ordinal logistic regression with predicted probabilities. Diagnostics were assessed with correct classification rate (CRR), polychoric correlations (PCC), Goodman and Kruskal Gamma (GKG), and Matthew's correlation coefficient (MCC).
Total 962 observations of paired data and 670 interval change data were available from 266 patient (mean age 35 years, mean disease duration 7 years, mean BASDAI 2.7, and mean ASDAS 2.1). Following ASDAS classes were observed: inactive disease 131 (13.6%), moderate disease activity 322 (33.5%), high disease activity 420 (43.65%), and very high disease activity 89 (9.25%). The three cut-offs generated for BASDAI were 0.8, 2.5, and 6 for BASDAI and those for ΔBASDAI were 2 and 4. The CRR for BASDAI cut-offs was 65.59 and that for ΔBASDAI was 54.9. For the BASDAI cut-offs, both PCC and GKG showed high values (> 0.85) and the MCC was 0.471.
In patients with axSpA, without any clinical or serological confounders, BASDAI values 0.8, 2.5, and 6 corresponded to ASDAS-CRP values 1.3, 2.1, and 3.5, respectively, and ΔBASDAI values of 2 and 4 correspond to ΔASDAS cut-offs of 1.1 and 2.
估计与 CRP 相关的强直性脊柱炎疾病活动评分（ASDAS）的切点值（1.3、2.1 和 3.5）对应的巴斯强直性脊柱炎疾病活动指数（BASDAI）的客观截断值，以及与 ASDAS 间隔变化（ΔASDAS）对应的间隔变化（ΔBASDAI）的截断值（1.1 和 2）。
本研究为多中心研究，共纳入 266 例接受托法替布 5mg 每日 2 次或阿达木单抗 40mg 每 2 周皮下注射治疗的活动期中轴型脊柱关节炎（axSpA）成年患者。分析了至少相隔 3 个月的 BASDAI 和 ASDAS 的配对数据以及这些参数的配对间隔变化。BASDAI 的截断值通过多项逻辑回归确定，而 ΔBASDAI 的截断值通过有序逻辑回归确定，并根据预测概率进行分类。通过正确分类率（CRR）、多质相关系数（PCC）、古德曼和克鲁斯卡尔伽马（GKG）和马修相关系数（MCC）评估诊断。
来自 266 例患者的 962 个配对数据和 670 个间隔变化数据可用于分析（平均年龄 35 岁，平均病程 7 年，平均 BASDAI 为 2.7，平均 ASDAS 为 2.1）。观察到以下 ASDAS 类别：无疾病活动 131 例（13.6%）、中度疾病活动 322 例（33.5%）、高度疾病活动 420 例（43.65%）和极高疾病活动 89 例（9.25%）。生成的 BASDAI 三个截断值分别为 0.8、2.5 和 6，而 ΔBASDAI 的截断值为 2 和 4。BASDAI 截断值的 CRR 为 65.59%，ΔBASDAI 的 CRR 为 54.9%。对于 BASDAI 截断值，PCC 和 GKG 均显示出较高的值（>0.85），MCC 为 0.471。
在 axSpA 患者中，无任何临床或血清学混杂因素，BASDAI 值 0.8、2.5 和 6 分别对应 ASDAS-CRP 值 1.3、2.1 和 3.5，而 ΔBASDAI 值 2 和 4 对应 ΔASDAS 的截断值为 1.1 和 2。
