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Item Type: | Article |
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Title: | 24 h-accelerometry in epidemiological studies : automated detection of non-wear time in comparison to diary information |
Creators Name: | Jaeschke, L., Luzak, A., Steinbrecher, A., Jeran, S., Ferland, M., Linkohr, B., Schulz, H. and Pischon, T. |
Abstract: | Estimation of physical activity using 24 h-accelerometry requires detection of accelerometer non-wear time (NWT). It is common practice to define NWT as periods >60 minutes of consecutive zero-accelerations, but this algorithm was originally developed for waking hours only and its applicability to 24 h-accelerometry is unclear. We investigated sensitivity and specificity of different algorithms to detect NWT in 24 h-accelerometry compared to diary in 47 ActivE and 559 KORA participants. NWT was determined with algorithms >60, >90, >120, >150, or >180 minutes of consecutive zero-counts. Overall, 9.1% (ActivE) and 15.4% (KORA) of reported NWT was >60 minutes. Sensitivity and specificity were lowest for the 60-min algorithm in ActivE (0.72 and 0.00) and KORA (0.64 and 0.08), and highest for the 180-min algorithm in ActivE (0.88 and 0.92) and for the 120-min algorithm in KORA (0.76 and 0.74). Nevertheless, when applying these last two algorithms, the overlap of accelerometry with any diary based NWT minutes was around 20% only. In conclusion, only a small proportion of NWT is >60 minutes. The 60-min algorithm is less suitable for NWT detection in 24 h-accelerometry because of low sensitivity, specificity, and small overlap with reported NWT minutes. Longer algorithms perform better but detect lower proportions of reported NWT. |
Keywords: | Accelerometry, Algorithms, Cross-Sectional Studies, Exercise, Public Health Surveillance, Sensitivity and Specificity |
Source: | Scientific Reports |
ISSN: | 2045-2322 |
Publisher: | Nature Publishing Group |
Volume: | 7 |
Number: | 1 |
Page Range: | 2227 |
Date: | 22 May 2017 |
Official Publication: | https://doi.org/10.1038/s41598-017-01092-w |
PubMed: | View item in PubMed |
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