Center for Rheumatology and Spine Diseases and the DANBIO Registry, Copenhagen University Hospital Rigshospitalet Glostrup Gentofte, Kildegårdsvej 28, 2900, Hellerup, Denmark.
Rheumatol Int. 2018 Mar;38(3):425-432. doi: 10.1007/s00296-017-3920-1. Epub 2018 Jan 3.
The study objective was to examine natural variation of the patient-reported outcome measures fatigue, pain, patient global assessment (PaGl) and the Bath Ankylosing Spondylitis Functional Index (BASFI) in patients with stable axial spondyloarthropathy (ax-SpA) defined on the basis of the Bath Spondylitis Ankylosing Disease Activity Index (BASDAI). 107 TNF-inhibitor treated stable ax-SpA patients were identified in the Danish rheumatology registry (DANBIO). According to the Assessment of SpondyloArthritis international Society (ASAS) response criteria, stable disease was defined as a change in BASDAI < 20 between two consecutive visits. Data on BASDAI, fatigue, pain, PaGl and BASFI (0-100) from such two visits were extracted for each patient. Lower and upper 95% limits of agreement (LLoA;ULoA) and the mean of intra-individual differences (the bias) were computed for each measure. Associations were described by linear correlations and standard errors of estimation. Mean BASDAI was 35.6 ± 23.8, mean BASDAI change 0.0 ± 9.7 (range - 19 to 19) and mean inter-visit time duration 16 ± 13 weeks. LLoA;ULoA [bias] for fatigue was - 37.4;36.2 [- 0.6], for pain - 34.1;32.5 [- 0.8], for PaGl - 35.7;32.9 [- 1.4] and for BASFI - 23.2;22.6 [- 0.3]. Intra-individual differences in fatigue, pain, BASFI and PaGl were not correlated with the inter-visit time duration, were poorly inter-correlated and were poorly correlated with baseline values and with changes in BASDAI. In conclusion, natural variation of patient-reported outcome measures was substantial and unpredictable in individual ax-SpA patients in steady state defined on the basis of BASDAI. Consequently, observed changes in the daily clinic should be interpreted with caution.
研究目的是检验基于 Bath 强直性脊柱炎活动指数（BASDAI）定义的稳定轴性脊柱关节炎（ax-SpA）患者的患者报告结局测量疲劳、疼痛、患者总体评估（PaGl）和 Bath 强直性脊柱炎功能指数（BASFI）的自然变异。在丹麦风湿病登记处（DANBIO）中确定了 107 例 TNF 抑制剂治疗的稳定 ax-SpA 患者。根据评估强直性脊柱炎国际协会（ASAS）反应标准，稳定疾病定义为连续两次就诊时 BASDAI 变化<20。从每位患者的两次就诊中提取 BASDAI、疲劳、疼痛、PaGl 和 BASFI（0-100）的数据。计算每个指标的下限和上限 95%一致性界限（LLOAs；ULOAs）和个体内差异的平均值（偏差）。描述关联的方法是线性相关和估计的标准误差。平均 BASDAI 为 35.6±23.8，平均 BASDAI 变化 0.0±9.7（范围-19 至 19），两次就诊之间的平均间隔时间为 16±13 周。疲劳的 LLOA；ULOA [偏差]为-37.4；36.2 [-0.6]，疼痛为-34.1；32.5 [-0.8]，PaGl 为-35.7；32.9 [-1.4]，BASFI 为-23.2；22.6 [-0.3]。疲劳、疼痛、BASFI 和 PaGl 的个体内差异与就诊间隔时间无相关性，相关性较差，与基线值和 BASDAI 的变化相关性较差。总之，在基于 BASDAI 定义的稳定状态下，个体 ax-SpA 患者的患者报告结局测量的自然变异是显著且不可预测的。因此，应谨慎解释日常临床观察到的变化。
