Table 5.

Results of the group by time interaction from the multilevel mixed model analyses

Questionnaire data	Estimate	SE	z	P > |z|	95% CI
ISI—insomnia (0 good sleep–28 poor sleep)	− 1.050	0.632	− 1.65	0.098	− 2.285	0.193
SMBQ—burnout (1 low–6 high burnout)	0.010	0.138	0.08	0.940	− 0.261	0.282
Diary data
Mean subjective sleep quality (1 very poor–5 very good)	0.006	0.078	0.07	0.943	− 0.148	0.159
Mean non-refreshing sleep (1 non refreshed–5 completely)	0.040	0.088	0.45	0.649	− 0.133	0.213
Stress/worries at bedtime (1 very worried–5 very calm)	− 0.030	0.052	− 0.56	0.575	− 0.132	0.073
Actigraphy data
Total sleep time (h)	− 0.031	0.104	− 0.30	0.766	− 0.234	0.173
Sleep efficiency (%)	0.321	1.011	0.32	0.751	− 1.66	2.302

All three data collection periods are included in the model

ISI Insomnia Severity Index, SMBQ Shirom–Melamed Burnout Questionnaire, SE standard error, CI confidence interval