Low levels of physical activity are implicated in low life expectancies of people receiving maintenance haemodialysis. Accelerometers are increasingly being used to quantify activity behaviours of this population but guidance to quality-assure such data is lacking. The objective of this study was to provide data processing and reduction recommendations to ensure accelerometer-derived outcomes are sufficiently reliable for interpretative analysis. Seventy people receiving maintenance haemodialysis (age 55.9 ± 15.7 years, 34% women, 23% diabetic) from a single outpatient renal unit volunteered for the study. Participants wore Actigraph GT3x and ActivPAL monitors during waking hours over seven days. Reliability of accelerometer output (normalised to wear-time) was assessed via intraclass correlation coefficient (ICC). The Spearman-Brown prophecy formula was subsequently applied to the ICCs to derive the minimum required accelerometer wear-time for each behavioural outcome. Monitor wear compliance was greater on dialysis compared to non-dialysis days (90% v 77%). Participants were significantly more active on non-dialysis days compared to dialysis days but there were no significant differences in estimated behaviours between days within the same condition. Average measure ICCs for all accelerometer outcomes were high (range 0.76–0.96). Computations indicated that habitual physical activity and sedentary behaviour could be estimated with a minimum reliability level of 0.80 from one dialysis day and two non-dialysis days, and at least eight hours monitor wear per day. Applying this rubric allowed 90% of participant data to be retained for further analysis. Regardless of accelerometer, one dialysis and two non-dialysis days data with a minimum of eight hours wear each day should enable habitual activity of people receiving maintenance haemodialysis to be characterised with acceptable reliability. These recommendations reconcile the tension between wear-time criteria stringency and retention of an adequately representative sample.

中文翻译：

---

用于可靠估计接受血液透析的人的身体活动和久坐行为的最短加速度计磨损时间。

低水平的身体活动与接受维持性血液透析的人的预期寿命低有关。加速度计越来越多地用于量化该人群的活动行为，但缺乏确保此类数据质量的指导。本研究的目的是提供数据处理和减少建议，以确保加速度计衍生的结果对于解释性分析足够可靠。来自一个门诊肾脏病房的 70 名接受维持性血液透析的人（年龄 55.9 ± 15.7 岁，34% 为女性，23% 为糖尿病患者）自愿参加了这项研究。参与者在超过 7 天的清醒时间内佩戴 Actigraph GT3x 和 ActivPAL 显示器。通过组内相关系数 (ICC) 评估加速度计输出的可靠性（按磨损时间归一化）。随后将 Spearman-Brown 预言公式应用于 ICC，以推导出每个行为结果所需的最小加速度计磨损时间。与非透析天数相比，透析时监测器的佩戴依从性更高（90% 对 77%）。与透析日相比，参与者在非透析日明显更活跃，但在相同条件下，不同日间的估计行为没有显着差异。所有加速度计结果的平均测量 ICC 值都很高（范围 0.76-0.96）。计算表明，习惯性的身体活动和久坐行为可以从一个透析日和两个非透析日以 0.80 的最低可靠性水平进行估计，并且每天至少有 8 小时的监测磨损。应用此标准可以保留 90% 的参与者数据以供进一步分析。不管加速度计如何，每天至少佩戴 8 小时的一次透析和两次非透析日数据应该能够使接受维持性血液透析的人的习惯性活动具有可接受的可靠性特征。这些建议调和了磨损时间标准的严格性与充分代表性样品的保留之间的紧张关系。