tailieunhanh - Báo cáo y học: "Measuring the impact of apnea and obesity on circadian activity patterns using functional linear modeling of actigraphy data"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Measuring the impact of apnea and obesity on circadian activity patterns using functional linear modeling of actigraphy data. | Wang et al. Journal of Circadian Rhythms 2011 9 11 http content 9 1 11 JOURNAL OF CIRCADIAN RHYTHMS RESEARCH Open Access Measuring the impact of apnea and obesity on circadian activity patterns using functional linear modeling of actigraphy data Jia Wang1 Hong Xian1 2 Amy Licis3 Elena Deych1 Jimin Ding4 Jennifer McLeland3 Cristina Toedebusch3 Tao Li1 Stephen Duntley3 and William Shannon1 Abstract Background Actigraphy provides a way to objectively measure activity in human subjects. This paper describes a novel family of statistical methods that can be used to analyze this data in a more comprehensive way. Methods A statistical method for testing differences in activity patterns measured by actigraphy across subgroups using functional data analysis is described. For illustration this method is used to statistically assess the impact of apnea-hypopnea index apnea and body mass index BMI on circadian activity patterns measured using actigraphy in 395 participants from 18 to 80 years old referred to the Washington University Sleep Medicine Center for general sleep medicine care. Mathematical descriptions of the methods and results from their application to real data are presented. Results Activity patterns were recorded by an Actical device Philips Respironics Inc. every minute for at least seven days. Functional linear modeling was used to detect the association between circadian activity patterns and apnea and BMI. Results indicate that participants in high apnea group have statistically lower activity during the day and that BMI in our study population does not significantly impact circadian patterns. Conclusions Compared with analysis using summary measures . average activity over 24 hours total sleep time Functional Data Analysis FDA is a novel statistical framework that more efficiently analyzes information from actigraphy data. FDA has the potential to reposition the focus of actigraphy data from general sleep assessment to rigorous