Table 2 Circadian parameters derived from actigraphy circadian computations
Variables | Explanations |
|---|---|
Cosinor analysis | |
 Acrophase | Time of maximum activity (peak). Express as clock time |
 Amplitude | Differences in distance from the peak to the nadir |
 MESOR | The mean activity level of the fitted curve |
Non-parametric analysis | |
 L5/M10 onset | Time of onset of the five least active hours (presumed to represent sleep) and the ten most active hours (presumed to represent daytime activity). Express as clock time |
 Intradaily variability (IV) | An index ranging from 0–1 quantifies the degree of rhythm fragmentation. A higher value reflects greater fragmentation, reflecting more daytime napping or nocturnal awakening |
 Interdaily stability (IS) | An index ranging from 0–1 reflects the synchronisation of rhythm to the light–dark cycle. A higher value reflects better synchronisation |
 Relative amplitude (RA) | Normalised differences in distance from L5 to M10. A higher value reflects the greater robustness of the circadian rhythm |