Measurement considerations of peak stepping cadence measures using national health and nutrition examination survey 2005-2006

Background: This study examined the optimal measurement conditions to obtain reliable peak cadence measures using the accelerometerdetermined step data from the National Health and Nutrition Examination Survey 2005-2006. Methods: A total of 1282 adults (> 17 years) who provided valid accelerometer data for 7 consecutive days were included. The peak 1-and 30-minute cadences were extracted. The sources of variance in peak stepping cadences were estimated using Generalizability theory analysis. A simulation analysis was conducted to examine the effect of the inclusion of weekend days. The optimal number of monitoring days to achieve 80% reliability for peak stepping cadences were estimated. Results: Intraindividual variability was the largest variance component of peak cadences for young and middle-aged adults aged < 60 years (50.55%-59.24%) compared with older adults aged < 60 years (31.62%-41.72%). In general, the minimum of 7 and 5 days of monitoring were required for peak 1-and 30-minute cadences among young and middle-aged adults, respectively, whereas 3 days of monitoring was sufficient for older adults to achieve the desired reliability (0.80). The inclusion of weekend days in the monitoring frame may not be practically important. Conclusions: The findings could be applied in future research as the reference measurement conditions for peak cadences.