BACKGROUND To evaluate the discordance in frailty classification between the frailty index (FI) and the physical frailty phenotype (PFP) and identify factors discriminating those with discordant frailty classification from each other and from those for whom the assessments agree. METHODS A prospective observational study of older adults aged 65 and older selected from Medicare eligibility lists in four U.S. communities (n = 5,362). The PFP was measured by the Cardiovascular Health Study PFP. Participants meeting three or more of the five criteria were deemed frail. The FI was calculated as the proportion of deficits in an a priori selected set of 48 measures, and participants were classified as frail if FI is greater than 0.35. RESULTS The prevalence of frailty was 7.0% by the PFP and 8.3% by the FI. Of the 730 deemed frail by either instrument, only 12% were in agreement, whereas 39% were classified as frail by the PFP, but not the FI, and 48% were classified as frail by the FI, but not the PFP. Participants aged 65-72 years or with greater disease burden were most likely to be characterized as being FI-frail, but not PFP-frail. The associations of frailty with age and mortality were stronger when frailty was measured by the PFP rather than the FI. CONCLUSIONS Despite comparable frailty prevalence between the PFP and the FI, there was substantial discordance in individual-level classification, with highest agreement existing only in the most vulnerable subset. These findings suggest that there are clinically important contexts in which the PFP and the FI cannot be used interchangeably.

中文翻译：

---

虚弱识别的差异：超越预测有效性。


背景 评估衰弱指数（FI）和身体衰弱表型（PFP）之间衰弱分类的不一致，并确定将衰弱分类不一致的人与评估一致的人区分开来的因素。方法 对从美国四个社区的 Medicare 资格名单中选出的 65 岁及以上老年人进行前瞻性观察研究 (n = 5,362)。 PFP 通过心血管健康研究 PFP 进行测量。满足五个标准中三个或三个以上的参与者被视为虚弱。 FI 计算为先验选定的 48 项措施中的赤字比例，如果 FI 大于 0.35，参与者将被归类为虚弱。结果 PFP 的虚弱患病率为 7.0%，FI 的虚弱患病率为 8.3%。在这两种工具认定为体弱的 730 人中，只有 12% 的人同意，而 39% 的人被 PFP（而非 FI）归类为体弱，48% 的人被 FI（而非 PFP）归类为体弱。年龄在 65-72 岁或疾病负担较大的参与者最有可能被描述为 FI 脆弱，但不是 PFP 脆弱。当通过 PFP 而不是 FI 来衡量衰弱时，衰弱与年龄和死亡率的关联更强。结论 尽管 PFP 和 FI 之间的衰弱患病率相当，但个人层面的分类存在很大不一致，只有最脆弱的子集存在最高的一致性。这些发现表明，在一些重要的临床情况下，PFP 和 FI 不能互换使用。