Table 4

Actigraphy data

CRFS casesControls
VariableMeanSDMeanSDp Value
Sleep
 Actual sleep time (h)06:0400:44:4106:0700:45:560.74
 Actual sleep (%)84.406.4182.4910.280.27
 Actual wake time (h)01:0700:28:2901:1100:30:310.48
 Actual wake (%)17.5110.2715.606.410.28
 Sleep efficiency (%)80.227.7378.4413.280.43
 Sleep latency (min)00:17:3200:20:2700:17:1900:27:360.97
 Average number of calculated sleep bouts23.736.6024.047.020.82
 Average number of calculated wake bouts23.776.6824.107.020.81
 Mean sleep bout time (min)00:33:0300:44:4100:19:2000:13:410.02
Activity
 Mean wake bout time (min)00:02:4300:00:4200:03:2500:00:280.19
 Average value of epoch intensity (24 h period)208.4887.22245.8296.320.04
 Difference in maximum and minimum activity198.8569.70218.5588.970.45
 Peak intensity of epoch11.915.0211.994.680.22
 Average of daytime (light) activity299.25131.18342.92119.920.03
 Time of night time (dark) activity117.7055.24148.7290.600.14
 Ratio of light to dark activity2.991.542.991.540.82
Circadian rhythm
 Interdaily stability0.530.120.570.150.16
 Interdaily variability0.860.210.830.210.14
 Least 5 (L5) active hours14751010234816340.50
 Most 10 (M10) active hours2248177742486587220.50
 Relative amplitude0.880.070.860.140.22
  • Sleep efficiency (%) is time asleep (as per algorithm) divided by total time in bed.

  • Sleep latency is time in bed before algorithm records the subject being asleep.

  • Average value of epoch intensity (24 h period): the recording is converted to and analysed as a cosine wave around a zero point.

  • Difference in maximum and minimum in activity corresponds to the difference between the peak and trough of the cosine wave.

  • Interdaily stability is a measure of consistency in daily activity over 7 days.

  • Interdaily variability is a measure of fragmentation of periods of rest and activity; normal value are <1 and calculated over 7 days.

  • L5 indicates the 5 h of calculated lowest activity over the 7-day average.

  • M10 indicates the 10 h of calculated greatest activity over the 7-day average.

  • Relative amplitude is a measure of the difference between L5 and M10 and thus an indication of overall level of activity over the 7-day period.

  • CRFS, cancer-related fatigue syndrome.