Department of Health Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UK.
Harefield Respiratory Research Group, Royal Brompton and Harefield Clinical Group, Guy's and St Thomas' NHS Foundation Trust, London, UK.
Respirology. 2023 Jul;28(7):649-658. doi: 10.1111/resp.14494. Epub 2023 Mar 23.
Gait speed is associated with survival in individuals with idiopathic pulmonary fibrosis (IPF). The extent to which four-metre gait speed (4MGS) decline predicts adverse outcome in IPF remains unclear. We aimed to examine longitudinal 4MGS change and identify a cut-point associated with adverse outcome.
In a prospective cohort study, we recruited 132 individuals newly diagnosed with IPF and measured 4MGS change over 6 months. Death/first hospitalization at 6 months were composite outcome events. Complete data (paired 4MGS plus index event) were available in 85 participants; missing 4MGS data were addressed using multiple imputation. Receiver-Operating Curve plots identified a 4MGS change cut-point. Cox proportional-hazard regression assessed the relationship between 4MGS change and time to event.
4MGS declined over 6 months (mean [95% CI] change: -0.05 [-0.09 to -0.01] m/s; p = 0.02). A decline of 0.07 m/s or more in 4MGS over 6 months had better discrimination for the index event than change in 6-minute walk distance, forced vital capacity, Composite Physiologic Index or Gender Age Physiology index. Kaplan-Meier curves demonstrated a significant difference in time to event between 4MGS groups (substantial decline: >-0.07 m/s versus minor decline/improvers: ≤-0.07 m/s; p = 0.007). Those with substantial decline had an increased risk of hospitalization/death (adjusted hazard ratio [95% CI] 4.61 [1.23-15.83]). Similar results were observed in multiple imputation analysis.
In newly diagnosed IPF, a substantial 4MGS decline over 6 months is associated with shorter time to hospitalization/death at 6 months. 4MGS change has potential as a surrogate endpoint for interventions aimed at modifying hospitalization/death.
步态速度与特发性肺纤维化（IPF）患者的生存率相关。四项步态速度（4MGS）下降预测 IPF 不良结局的程度尚不清楚。我们旨在研究纵向 4MGS 变化，并确定与不良结局相关的切点。
在一项前瞻性队列研究中，我们招募了 132 名新诊断为 IPF 的患者，并在 6 个月内测量了 4MGS 的变化。6 个月时死亡/首次住院是复合终点事件。85 名参与者的完整数据（配对的 4MGS 加指数事件）可用；缺失的 4MGS 数据通过多重插补处理。接收器工作特征曲线确定 4MGS 变化的切点。Cox 比例风险回归评估 4MGS 变化与时间事件的关系。
4MGS 在 6 个月内下降（平均[95%CI]变化：-0.05[-0.09 至-0.01]m/s；p=0.02）。4MGS 在 6 个月内下降 0.07m/s 或更多对指数事件的预测优于 6 分钟步行距离、用力肺活量、综合生理指数或性别年龄生理指数的变化。Kaplan-Meier 曲线显示 4MGS 组之间的时间事件存在显著差异（显著下降：> -0.07m/s 与轻微下降/改善：≤ -0.07m/s；p=0.007）。那些有显著下降的患者有更高的住院/死亡风险（调整后的危险比[95%CI]4.61[1.23-15.83]）。多重插补分析也得到了类似的结果。
在新诊断的 IPF 中，6 个月内 4MGS 显著下降与 6 个月内住院/死亡的时间缩短相关。4MGS 变化有可能成为旨在改变住院/死亡的干预措施的替代终点。
