Falls and Balance Research Group, Neuroscience Research Australia, University of New South Wales, Sydney, Australia; Institute for Biomedicine of Aging, Friedrich-Alexander-University Erlangen-Nürnberg, Nuremberg, Germany.
Falls and Balance Research Group, Neuroscience Research Australia, University of New South Wales, Sydney, Australia.
J Am Med Dir Assoc. 2017 Aug 1;18(8):719-725. doi: 10.1016/j.jamda.2017.03.010. Epub 2017 May 16.
Response inhibition, an important executive function, has been identified as a risk factor for falls in older people. This study investigated whether step tests that include different levels of response inhibition differ in their ability to predict falls and whether such associations are mediated by measures of attention, speed, and/or balance.
A cohort study with a 12-month follow-up was conducted in community-dwelling older people without major cognitive and mobility impairments. Participants underwent 3 step tests: (1) choice stepping reaction time (CSRT) requiring rapid decision making and step initiation; (2) inhibitory choice stepping reaction time (iCSRT) requiring additional response inhibition and response-selection (go/no-go); and (3) a Stroop Stepping Test (SST) under congruent and incongruent conditions requiring conflict resolution. Participants also completed tests of processing speed, balance, and attention as potential mediators.
Ninety-three of the 212 participants (44%) fell in the follow-up period. Of the step tests, only components of the iCSRT task predicted falls in this time with the relative risk per standard deviation for the reaction time (iCSRT-RT) = 1.23 (95%CI = 1.10-1.37). Multiple mediation analysis indicated that the iCSRT-RT was independently associated with falls and not mediated through slow processing speed, poor balance, or inattention.
Combined stepping and response inhibition as measured in a go/no-go test stepping paradigm predicted falls in older people. This suggests that integrity of the response-selection component of a voluntary stepping response is crucial for minimizing fall risk.
反应抑制是一种重要的执行功能，已被确定为老年人跌倒的危险因素。本研究旨在探讨包含不同程度反应抑制的步测试验在预测跌倒方面的能力是否存在差异，以及这些关联是否通过注意力、速度和/或平衡的测量来介导。
本研究为一项队列研究，随访时间为 12 个月，研究对象为无明显认知和移动障碍的社区居住老年人。参与者接受了 3 种步测试验：（1）需要快速决策和起始步的选择步反应时（CSRT）；（2）需要额外反应抑制和反应选择（Go/No-Go）的抑制选择步反应时（iCSRT）；（3）在一致和不一致条件下需要解决冲突的斯特鲁普步测试验（SST）。参与者还完成了处理速度、平衡和注意力测试，作为潜在的中介因素。
在随访期间，212 名参与者中有 93 名（44%）跌倒。在这些步测试验中，只有 iCSRT 任务的组成部分在这段时间内预测了跌倒，反应时间（iCSRT-RT）每标准差的相对风险比为 1.23（95%CI = 1.10-1.37）。多重中介分析表明，iCSRT-RT 与跌倒独立相关，而不受处理速度慢、平衡差或注意力不集中的影响。
在 Go/No-Go 测试步测范式中测量的综合踏步和反应抑制可预测老年人跌倒。这表明，自愿踏步反应的反应选择组件的完整性对于降低跌倒风险至关重要。
