BACKGROUND age-adapted definition of chronic kidney disease (CKD) does not take individual risk factors into account. We aimed at investigating whether functional impairments influence CKD stage at which mortality increases among older people. METHODS our series consisted of 2,372 outpatients aged 75 years or more enrolled in a multicentre international prospective cohort study. The study outcome was 24-month mortality. Kidney function was assessed by estimated glomerular filtration rate (eGFR) and albumin-to-creatinine ratio (ACR). Geriatric assessments included handgrip strength, short physical performance battery (SPPB), cognitive impairment, dependency in basic activities of daily living (BADL) and risk of malnutrition. Analysis was carried out by Cox regression, before and after stratification by individual functional impairments. Survival trees including kidney function and functional impairments were also investigated, and their predictivity assessed by C-index. RESULTS overall, mortality was found to increase starting from eGFR = 30-44.9 ml/min/1.73 m2 (hazard ratio [HR] = 3.28, 95% confidence interval [CI] = 1.81-5.95) to ACR = 30-300 mg/g (HR = 1.96, 95%CI = 1.23-3.10). However, in survival trees, an increased risk of mortality was observed among patients with impaired handgrip and eGFR = 45-59.9 ml/min/1.73 m2, as well as patients with ACR < 30 mg/g and impaired handgrip and SPPB. Survival tree leaf node membership had greater predictive accuracy (C-index = 0.81, 95%CI = 0.78-0.84 for the eGFR survival tree and C-index = 0.77, 95%CI = 0.71-0.81 for the ACR survival tree) in comparison with that of individual measures of kidney function. CONCLUSIONS physical performance helps to identify a proportion of patients at an increased risk of mortality despite a mild-moderate impairment in kidney function and improves predictive accuracy of individual measures of kidney function.

中文翻译：

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老年评估对慢性肾脏病分期与老年人死亡率之间关系的相关性：多中心队列研究的二次分析。

背景慢性肾病（CKD）的年龄适应定义没有考虑个体风险因素。我们旨在调查功能障碍是否会影响老年人死亡率增加的 CKD 阶段。方法 我们的系列包括 2,372 名年龄在 75 岁或以上的门诊患者，他们参加了一项多中心国际前瞻性队列研究。研究结果为 24 个月死亡率。通过估计的肾小球滤过率 (eGFR) 和白蛋白肌酐比 (ACR) 评估肾功能。老年人评估包括握力、体能短电池 (SPPB)、认知障碍、对日常生活基本活动的依赖 (BADL) 和营养不良风险。在按个体功能障碍分层之前和之后，通过 Cox 回归进行分析。还研究了包括肾功能和功能障碍在内的生存树，并通过 C 指数评估了它们的预测性。结果 总体而言，发现死亡率从 eGFR = 30-44.9 ml/min/1.73 m2（风险比 [HR] = 3.28，95% 置信区间 [CI] = 1.81-5.95）到 ACR = 30-300 mg/ g (HR = 1.96, 95%CI = 1.23-3.10)。然而，在生存树中，在握力受损且 eGFR = 45-59.9 ml/min/1.73 m2 的患者以及 ACR < 30 mg/g 且握力和 SPPB 受损的患者中观察到死亡风险增加。相比之下，生存树的叶子节点成员具有更高的预测准确性（eGFR 生存树的 C-index = 0.81, 95%CI = 0.78-0.84 和 ACR 生存树的 C-index = 0.77, 95%CI = 0.71-0.81）与肾功能的个别测量。