Gruen Margaret E, Alfaro-Córdoba Marcela, Thomson Andrea E, Worth Alicia C, Staicu Ana-Maria, Lascelles B Duncan X
Comparative Pain Research Program, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America.
Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina, United States of America.
PLoS One. 2017 Jan 18;12(1):e0169576. doi: 10.1371/journal.pone.0169576. eCollection 2017.
Accelerometry is used as an objective measure of physical activity in humans and veterinary species. In cats, one important use of accelerometry is in the study of therapeutics designed to treat degenerative joint disease (DJD) associated pain, where it serves as the most widely applied objective outcome measure. These analyses have commonly used summary measures, calculating the mean activity per-minute over days and comparing between treatment periods. While this technique has been effective, information about the pattern of activity in cats is lost. In this study, functional data analysis was applied to activity data from client-owned cats with (n = 83) and without (n = 15) DJD. Functional data analysis retains information about the pattern of activity over the 24-hour day, providing insight into activity over time. We hypothesized that 1) cats without DJD would have higher activity counts and intensity of activity than cats with DJD; 2) that activity counts and intensity of activity in cats with DJD would be inversely correlated with total radiographic DJD burden and total orthopedic pain score; and 3) that activity counts and intensity would have a different pattern on weekends versus weekdays.
Results showed marked inter-cat variability in activity. Cats exhibited a bimodal pattern of activity with a sharp peak in the morning and broader peak in the evening. Results further showed that this pattern was different on weekends than weekdays, with the morning peak being shifted to the right (later). Cats with DJD showed different patterns of activity from cats without DJD, though activity and intensity were not always lower; instead both the peaks and troughs of activity were less extreme than those of the cats without DJD. Functional data analysis provides insight into the pattern of activity in cats, and an alternative method for analyzing accelerometry data that incorporates fluctuations in activity across the day.
加速度计被用作人类和兽医物种身体活动的客观测量指标。在猫中，加速度计的一个重要用途是用于研究旨在治疗与退行性关节病（DJD）相关疼痛的疗法，它是应用最广泛的客观结果测量指标。这些分析通常使用汇总测量方法，计算数天内每分钟的平均活动量并在不同治疗阶段之间进行比较。虽然这种技术很有效，但有关猫活动模式的信息却丢失了。在本研究中，功能数据分析被应用于来自有（n = 83）和无（n = 15）DJD的客户拥有的猫的活动数据。功能数据分析保留了24小时内活动模式的信息，从而深入了解随时间的活动情况。我们假设：1）没有DJD的猫比患有DJD的猫具有更高的活动计数和活动强度；2）患有DJD的猫的活动计数和活动强度与总的放射学DJD负担和总的骨科疼痛评分呈负相关；3）活动计数和强度在周末与工作日会有不同的模式。
结果显示猫之间的活动存在显著差异。猫表现出双峰活动模式，早上有一个尖峰，晚上有一个更宽的峰值。结果还表明，这种模式在周末与工作日不同，早上的峰值向右（更晚）移动。患有DJD的猫与没有DJD的猫表现出不同的活动模式，尽管活动和强度并不总是更低；相反，活动的峰值和谷值都不如没有DJD的猫那么极端。功能数据分析为猫的活动模式提供了深入了解，并为分析加速度计数据提供了一种替代方法，该方法纳入了一天中活动的波动情况。
