Ray Meredith A, Youngstedt Shawn D, Zhang Hongmei, Robb Sara Wagner, Harmon Brook E, Jean-Louis Girardin, Cai Bo, Hurley Thomas G, Hébert James R, Bogan Richard K, Burch James B
Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.
College of Nursing and Health Innovation, Arizona State University, Phoenix, AZ, USA ; Phoenix VA Health Care System, Phoenix, AZ, USA ; School of Nutrition and Health Promotion, Arizona State University, Phoenix, AZ, USA.
Sleep Sci. 2014 Jun;7(2):74-81. doi: 10.1016/j.slsci.2014.09.007.
Improving and validating sleep scoring algorithms for actigraphs enhances their usefulness in clinical and research applications. The MTI device (ActiGraph, Pensacola, FL) had not been previously validated for sleep. The aims were to (1) compare the accuracy of sleep metrics obtained via wrist- and hip-mounted MTI actigraphs with polysomnographic (PSG) recordings in a sample that included both normal sleepers and individuals with presumed sleep disorders; and (2) develop a novel sleep scoring algorithm using spline regression to improve the correspondence between the actigraphs and PSG.
Original actigraphy data were amplified and their pattern was estimated using a penalized spline. The magnitude of amplification and the spline were estimated by minimizing the difference in sleep efficiency between wrist- (hip-) actigraphs and PSG recordings. Sleep measures using both the original and spline-modified actigraphy data were compared to PSG using the following: mean sleep summary measures; Spearman rank-order correlations of summary measures; percent of minute-by-minute agreement; sensitivity and specificity; and Bland-Altman plots.
The original wrist actigraphy data showed modest correspondence with PSG, and much less correspondence was found between hip actigraphy and PSG. The spline-modified wrist actigraphy produced better approximations of interclass correlations, sensitivity, and mean sleep summary measures relative to PSG than the original wrist actigraphy data. The spline-modified hip actigraphy provided improved correspondence, but sleep measures were still not representative of PSG.
The results indicate that with some refinement, the spline regression method has the potential to improve sleep estimates obtained using wrist actigraphy.
改进并验证用于活动记录仪的睡眠评分算法可提高其在临床和研究应用中的效用。MTI设备（ActiGraph，佛罗里达州彭萨科拉）此前尚未针对睡眠进行过验证。目标是：（1）在一个既包括正常睡眠者又包括疑似睡眠障碍个体的样本中，比较通过腕部和髋部佩戴的MTI活动记录仪获得的睡眠指标与多导睡眠图（PSG）记录的准确性；（2）使用样条回归开发一种新颖的睡眠评分算法，以改善活动记录仪与PSG之间的对应关系。
对原始活动记录仪数据进行放大，并使用惩罚样条估计其模式。通过最小化腕部（髋部）活动记录仪与PSG记录之间的睡眠效率差异来估计放大倍数和样条。使用以下方法将原始和样条修正后的活动记录仪数据的睡眠测量结果与PSG进行比较：平均睡眠汇总测量；汇总测量的斯皮尔曼等级相关性；逐分钟一致性百分比；敏感性和特异性；以及布兰德-奥特曼图。
原始腕部活动记录仪数据与PSG显示出适度的对应关系，而髋部活动记录仪与PSG之间的对应关系则少得多。与原始腕部活动记录仪数据相比，样条修正后的腕部活动记录仪在类内相关性、敏感性和平均睡眠汇总测量方面相对于PSG产生了更好的近似值。样条修正后的髋部活动记录仪提供了更好的对应关系，但睡眠测量结果仍不能代表PSG。
结果表明，经过一些改进，样条回归方法有可能改善使用腕部活动记录仪获得的睡眠估计。
