Table 3.

Estimated group means and tests of effects, taken from a multilevel analysis of the secondary outcome measures using an intention to treat approach

	Estimated group means						Tests of effects								Cohen’s d between groups
	Intervention			Control			Group			Time			Group * Time
	Mean	SE	95% CI	Mean	SE	95% CI	F	P value	df	F	P value	df	F	P value	Post	Follow-up
PSS							0.08	0.78	175.63	0.52	0.60	144.83	2.24	0.11	0.22	0.01
Baseline	18.34	0.75	16.87 to 19.81	17.77	0.66	16.48 to 19.07
Post	16.95	0.70	15.56 to 18.34	18.23	0.66	16.93 to 19.53
Follow-up	17.64	0.78	16.10 to 19.18	17.63	0.70	16.25 to 19.01
SMBQ Tense							0.05	0.82	191.85	2.78	0.07	148.94	0.89	0.41	0.03	0.14
Baseline	3.83	0.13	3.58 to 4.08	3.75	0.12	3.51 to 3.99
Post	3.66	0.14	3.38 to 3.94	3.69	0.14	3.42 to 3.96
Follow-up	3.82	0.15	3.54 to 4.11	3.98	0.13	3.72 to 4.24
SMBQ Listlessness							1.99	0.16	190.88	0.59	0.56	150.50	2.89	0.06	0.39	0.15
Baseline	4.06	0.13	3.81 to 4.31	4.11	0.12	3.88 to 4.35
Post	3.81	0.12	3.57 to 4.05	4.21	0.12	3.98 to 4.45
Follow-up	3.99	0.14	3.72 to 4.27	4.16	0.13	3.91 to 4.41
DBAS							1.32	0.25	153.20	1.15	0.32	129.95	2.94	0.06	0.26	0.32
Baseline	5.34	0.20	4.94 to 5.74	5.27	0.19	4.89 to 5.65
Post	4.91	0.23	4.46 to 5.36	5.36	0.21	4.94 to 5.79
Follow-up	5.00	0.23	4.54 to 5.45	5.51	0.21	5.10 to 5.93

Factor labels in tests of effects: Group=Intervention vs Control, Time=Baseline vs Post vs Follow-up. Df (df) for Time and Group*time are identical.

DBAS, Dysfunctional Beliefs and Attitudes about Sleep, 0 do not agree—10 do fully agree; Mean, modelled mean values; PSS, Perceived Stress Scale, 0 never—40 very often; SMBQ, Shirom-Melamed Burn-out Questionnaire.