Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2.
Division of Geriatric Medicine, Dalhousie University, Halifax, Nova Scotia, Canada B3H 2E1.
Mech Ageing Dev. 2021 Oct;199:111570. doi: 10.1016/j.mad.2021.111570. Epub 2021 Sep 10.
measures of health quantify the aging process of individuals. They should be interpretable, associated with future adverse outcomes, and straightforward to assemble. We use the rank-ordering of risk within a population to construct a quantile frailty index (QFI) that avoids dichotomization, is convenient and interpretable, and is associated with adverse outcomes. We show that the QFI outperforms previous frailty index (FI) measures on cross-sectional laboratory data (NHANES, CSHA, and ELSA). We construct the QFI by ranking the risk of individuals with respect to a reference population. Sex-specific reference populations narrow male-female FI differences as a function of age, and improve predictive performance. With a fixed reference population of 80-85 year olds, our QFI appears similar to earlier FI measures. With an age-matched reference population for each individual, we obtain a QFI that contains very little age information and that has similar predictive performance as other age-controlled FI measures. Adding age as an auxiliary variable leads to significantly better performance. We conclude that age should be controlled for when evaluating the predictive performance of summary measures of health. This is straight-forward to do with the QFI.
健康测量指标量化了个体的衰老过程。它们应该具有可解释性、与未来不良结局相关，并且易于收集。我们使用人群中风险的排序来构建一个避免二分法的分位数脆弱性指数 (QFI)，它方便且易于解释，并与不良结局相关。我们表明，QFI 在横断面实验室数据 (NHANES、CSHA 和 ELSA) 上优于以前的脆弱性指数 (FI) 测量。我们通过对参考人群中的个体进行风险排序来构建 QFI。性别特异性参考人群缩小了男性和女性 FI 差异随年龄的变化，提高了预测性能。使用 80-85 岁的固定参考人群，我们的 QFI 似乎与早期的 FI 测量相似。对于每个个体使用年龄匹配的参考人群，我们得到一个 QFI，其中包含很少的年龄信息，并且与其他年龄控制的 FI 测量具有相似的预测性能。添加年龄作为辅助变量会导致性能显著提高。我们得出结论，在评估健康综合测量指标的预测性能时，应该控制年龄。这对于 QFI 来说非常简单。
