Table 4.

Mental health and physiological outcomes for simplified sleep restriction versus control at baseline and 6 months. Data presented as mean (SD)

	Simplified sleep restriction			Control			Difference between the groupsb,d,e (95% CI) P-value
	Baseline score,an= 46	6-month score,an= 43	Mean change (95% CI)b,c,d	Baseline score,an= 51	6-month score,an= 50	Mean change (95% CI)b,c,d
Mental health outcomes
PHQ-9 depression score	4.98 (2.76)	2.93 (2.39)	2.19 (−3.21, −1.17)	5.31 (2.80)	3.62 (2.69)	−1.66 (−2.54 to −0.78)	−0.53 (−1.77 to 0.71) 0.40
GAD-7 anxiety score	3.33 (3.06)	1.47 (1.88)	−1.76 (−2.59 to −0.92)	3.41 (2.45)	2.56 (2.35)	−0.84 (−1.56 to −0.12)	−0.92 (−1.93 to 0.10) 0.08
Physiological measures
Systolic blood pressure, mmHg	122.24 (2.06)	121.21 (2.15)	−1.33 (−4.28 to 1.63)	123.88 (1.87)f	125.06 (1.97)g	0.25 (−3.48 to 3.98)h	−1.58 (−6.34 to 3.19) 0.50
Diastolic blood pressure, mmHg	75.52 (1.53)	74.51 (1.42)	−1.30 (−3.29 to 0.68)	75.62 (1.27)	74.92 (1.48)g	−1.46 (−3.97 to 1.05)h	0.16 (−3.05 to 3.37) 0.90
Heart rate, beats per minute	68.91 (1.45)	69.47 (1.57)	0.72 (−1.98 to 3.43)	73.29 (1.52)	69.61 (1.37)g	−3.82 (−6.45 to−1.19)g	4.54 (0.81 to 8.27) 0.02

Statistically significant results are in bold.

^aObserved (raw) data.

^bMultiple linear regression adjusted for age, sex, and baseline insomnia severity (using Insomnia Severity Index score²⁶).

^cLeast square mean for change from baseline to 6-month score.

^dDifferences in physiological measures calculated from t-test procedure in SAS.

^eLeast square mean difference for change from baseline to 6-month score between sleep restriction and control group.

^fn = 50 due to machine error.

^gn = 49.

^hn = 48. PHQ-9 = Patient Health Questionnaire-9. GAD-7 = Generalized Anxiety Disorders-7.³⁴