Supplementary Material for: Heart Rate Variability for Evaluating Psychological Stress Changes in Healthy Adults: A Scoping Review

The utility of heart rate variability (HRV) for characterizing psychological stress is primarily impacted by methodological considerations such as study populations, experienced versus induced stress, and method of stress assessment. Here, we review studies on the associations between HRV and psychological stress, examining the nature of stress, ways stress was assessed, and HRV metrics used. The review was performed according to the PRISMA guidelines on select databases. Studies that examined the HRV-stress relationship via repeated measurements and validated psychometric instruments were included (<i>n</i> = 15). Participant numbers and ages ranged between 10 and 403 subjects and 18 and 60 years, respectively. Both experimental (<i>n</i> = 9) and real-life stress (<i>n</i> = 6) have been explored. While RMSSD was the most reported HRV metric (<i>n</i> = 10) significantly associated with stress, other metrics, including LF/HF (<i>n</i> = 7) and HF power (<i>n</i> = 6) were also reported. Various linear and nonlinear HRV metrics have been utilized, with nonlinear metrics used less often. The most frequently used psychometric instrument was the State-Trait Anxiety Inventory (<i>n</i> = 10), though various other instruments have been reported. In conclusion, HRV is a valid measure of the psychological stress response. Standard stress induction and assessment protocols combined with validated HRV measures in different domains will improve the validity of findings.

心率变异性（heart rate variability, HRV）用于表征心理应激的效用，主要受方法学因素影响，例如研究人群、自然应激与诱发应激的差异，以及应激评估方法等。本研究针对HRV与心理应激之间的关联展开综述，重点探讨应激的本质、应激评估方式以及所采用的HRV指标。本综述依据PRISMA指南，在选定的数据库中开展文献检索。纳入通过重复测量与经过验证的心理测评工具探究HRV与应激关联的研究，共计15项。纳入研究的参与者人数与年龄范围分别为10至403名，以及18至60岁。研究涵盖了诱发应激（共9项）与自然生活应激（共6项）两种类型。尽管均方根连续差（RMSSD）是报告最多的与应激显著相关的HRV指标（共10项），但其他指标同样被报道，包括低频/高频功率比（LF/HF，共7项）与高频功率（HF power，共6项）。研究中采用了多种线性与非线性HRV指标，其中非线性指标的使用频率相对较低。最常用的心理测评工具为状态-特质焦虑问卷（State-Trait Anxiety Inventory，共10项），不过研究中也使用了多种其他测评工具。综上，HRV可作为心理应激反应的有效测评指标。在不同研究领域中，采用标准化的应激诱发与评估方案，并结合经过验证的HRV测评方法，将有助于提升研究结果的效度。