Background Monitoring trajectories of intrinsic capacity (IC) in older adults has been suggested by the World Health Organization as a means to inform prevention to avoid or delay negative health outcomes. Due to a lack of longitudinal studies, it is currently unclear how IC changes over time and whether repeatedly measured IC predicts negative health outcomes. Methods Based on 4 751 repeated observations of IC (range = 0–100) during 21 years of follow-up among 754 older adults 70 and older, we assessed longitudinal trajectories of IC, and whether time-varying IC predicted the risk of chronic activities of daily living disability, long-term nursing home stay, and mortality using joint models. Results Average IC declined progressively from 77 to 11 points during follow-up, with substantial heterogeneity between older adults. Adjusted for sociodemographics and chronic diseases, a 1-point lower IC value was associated with a 7% increase in the risk of activities of daily living disability, a 6% increase in the risk of a nursing home stay, and a 5% increase in mortality. Accuracy for 5- and 10-year predictions based on up to 3 repeated measurements of IC ranged between moderate and good (area under the receiver operating characteristic curve = 0.76–0.82). Conclusions Our study indicates that IC declines progressively and that it predicts negative health outcomes among older adults. Therefore, regular monitoring of IC could work as an early warning system informing preventive efforts.

中文翻译：

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内在能力预测老年人的负面健康结果

背景 世界卫生组织建议监测老年人内在能力 (IC) 的轨迹，作为预防或延迟负面健康结果的一种手段。由于缺乏纵向研究，目前尚不清楚 IC 如何随时间变化，以及反复测量的 IC 是否能预测负面的健康结果。方法 基于对 754 名 70 岁及以上老年人的 21 年随访期间对 IC 的 4 751 次重复观察（范围 = 0-100），我们评估了 IC 的纵向轨迹，以及随时间变化的 IC 是否可以预测慢性活动的风险使用联合模型对日常生活残疾、长期疗养院住宿和死亡率进行评估。结果 随访期间，平均 IC 从 77 点逐渐下降至 11 点，老年人之间存在显着异质性。经社会人口统计学和慢性疾病调整后，IC 值降低 1 点与日常生活残疾活动风险增加 7%、在疗养院住院风险增加 6% 和生活障碍风险增加 5% 相关。死亡。基于多达 3 次重复测量 IC 的 5 年和 10 年预测的准确度介于中等和良好之间（接受者操作特征曲线下面积 = 0.76-0.82）。结论 我们的研究表明，IC 逐渐下降，它预示着老年人的负面健康结果。因此，定期监测 IC 可以作为预警系统，为预防工作提供信息。死亡率增加 5%。基于多达 3 次重复测量 IC 的 5 年和 10 年预测的准确度介于中等和良好之间（接受者操作特征曲线下面积 = 0.76-0.82）。结论 我们的研究表明，IC 逐渐下降，它预示着老年人的负面健康结果。因此，定期监测 IC 可以作为预警系统，为预防工作提供信息。死亡率增加 5%。基于多达 3 次重复测量 IC 的 5 年和 10 年预测的准确度介于中等和良好之间（接受者操作特征曲线下面积 = 0.76-0.82）。结论 我们的研究表明，IC 逐渐下降，它预示着老年人的负面健康结果。因此，定期监测 IC 可以作为预警系统，为预防工作提供信息。