Ibañez Dominique, Urowitz Murray B, Gladman Dafna D
University of Toronto Lupus Clinic, Centre for Prognosis Studies in the Rheumatic Diseases, Toronto Western Hospital, 399 Bathurst Street, EC 5-034, Toronto, Ontario, Canada M5T 2S8.
J Rheumatol. 2003 Sep;30(9):1977-82.
To develop a measurement of lupus disease activity over time.
We studied patients from the University of Toronto Lupus Clinic with "regular" followup, defined as having been in the clinic for at least 3 visits and never having been away from the clinic for a period exceeding 18 consecutive months. For each visit, disease activity was evaluated with the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K). The common approach to summarize over multiple visits by calculating a mean ignores the presence of varying time intervals between visits. We used the adjusted mean SLEDAI-2K (AMS), determined by the calculation of the area under the curve of SLEDAI-2K over time by adding the area of each of the blocks of visit interval and then dividing by the length of time for the whole period. The resulting AMS has the same units as the original SLEDAI-2K. A time-dependent covariate survival analysis was done to test which of AMS, SLEDAI-2K at presentation, sex, and age at diagnosis is the best predictor of mortality.
A total of 575 patients with regular followup were included. Only AMS and age at diagnosis were significant predictors. Odds ratio (OR) and 95% confidence intervals (CI) for AMS: OR 1.15 (CI 1.09, 1.20), p = 0.0001; age at diagnosis: OR 1.05 (CI 1.03, 1.06), p = 0.0001.
AMS represents an average disease activity measure over time and is strongly associated with mortality.
制定一种随时间推移测量狼疮疾病活动度的方法。
我们研究了多伦多大学狼疮诊所接受“定期”随访的患者，“定期”随访定义为至少就诊3次且从未连续18个月以上未到诊所就诊。每次就诊时，使用2000年系统性红斑狼疮疾病活动指数（SLEDAI - 2K）评估疾病活动度。通过计算平均值来汇总多次就诊情况的常用方法忽略了就诊之间时间间隔的差异。我们使用调整后的平均SLEDAI - 2K（AMS），其计算方法是将每次就诊间隔时间段的SLEDAI - 2K曲线下面积相加，然后除以整个时间段的时长，从而得出随时间变化的SLEDAI - 2K曲线下面积。所得的AMS与原始SLEDAI - 2K具有相同的单位。进行了时间依赖性协变量生存分析，以检验AMS、就诊时的SLEDAI - 2K、性别和诊断时的年龄中哪一个是死亡率的最佳预测指标。
共纳入575例接受定期随访的患者。只有AMS和诊断时的年龄是显著的预测指标。AMS的比值比（OR）和95%置信区间（CI）：OR 1.15（CI 1.09，1.20），p = 0.0001；诊断时的年龄：OR 1.05（CI 1.03，1.06），p = 0.0001。
AMS代表了随时间推移的平均疾病活动度测量值，并且与死亡率密切相关。
