Table 1. Correlations and differences between subjective and objective sleep parameters.

		mean (standard deviation)		Pearson’s correlation coefficient (p value)	difference† (95% confidence interval)
	n	subjective (daily records)	objective (Actiwatch®)
Sleep latency (min)	42	15 (10.7)	7.3 (8.5)	0.49 (<0.001)	7.67 (4.64-10.71)
Sleep start (hr:min)	42	23:49 (0:53)	23:47 (0:52)	0.99 (<0.001)	0:02 (-0:01-0:05)
Sleep end (hr:min)	42	7:00 (0:26)	6:58 (0:26)	0.99 (<0.001)	0:02 (0:01-0:03)
Assumed sleep (min)	42	424.1 (46.4)	415.9 (45.0)	0.97 (<0.001)	8.19 (4.93-11.45)

† : subjective value minus objective value