Table 2. Included studies, study designs and sleep quality improvement effects (N=13).

Author and year	TST	SOL	SE	Proportion of deep sleep	Subjective sleep quality	Symptom relief	Other indirect improvement
Single-arm pre–post studies
Zhang et al, 201573		Significantly reduced the SOL for people with difficulty in falling asleep (p=1.22e−04, Wilcoxon signed-rank test).
Wei et al, 202375	Significantly increased TST for female participants (p=0.035).		Significantly improved SE for female participants (B=2.666, sig=0.033).	Significantly decreased non-rapid eye movement N2 proportion (B=2.666, sig=0.033), and increased non-rapid eye movement N3 proportion (B=2.8, sig=0.078). Decreased ANS activity during N3 sleep.	Significantly improved the self-rated sleep quality for female participants (p=0.025).
Verhaert et al, 201376			Spinal alignment was significantly improved in the active support condition.		The group with active control of bed attributes (7.00±0.87) scored higher on subjective perceived sleep quality than the reference night group without control of bed attributes (5.67±1.41).
Tang et al, 202372	Increased total sleep duration.	Shorter sleep latency.		Average heart rate and respiratory rate stabilised, and the number of body movements decreased.			Offered help, suggestions and care plans based on disease risk prediction (including sleep disorders such as OSA).
Hu et al, 202167			Long sleep continuity; Frequent nap variables.				Better adherence, incorporating medically advised interventions into the care system, and improving overall quality of life.
Ferrer-Lluis et al, 202169						The percentage of time subjects spent supine before and after postural therapy (45.6% → 2%).
Pilot study
Zhao et al, 202074				The users’ deep sleep time and deep sleep frequency increased significantly.	Sleep score increased and the effect was more obvious (81 → 92; 92 → 98).
Van der Loos et al, 200364						Gently encourages a person to roll over to alleviate snoring and OSA.
He et al, 202268						The average snoring time (135 → 15 min).
Development study
Liao et al, 202465		Effectively promoted restful sleep and improved nightly rest in noisy environments.
Kim et al, 201966							Set the temperature at the optimal sleep condition and monitored the sleep condition based on the telemedicine system.
RCT
Donati et al, 202170	Sleeping hours (6 hours to almost 8 hours)				PGWBI: 3.4 → 3.9. PSQI: 1.9 → 2.3. PedsQL: 1.3 → 0.7.
Crossover RCT
Bogan et al, 201771					FOSQ-10. SensAwake ON compared with baseline (↑, 4.63±0.99). SensAwake OFF compared with baseline (↑, 6.47±0.90).

ANS, autonomic nervous system; FQSQ-10, Short Functional Outcomes of Sleep Questionnaire; OSA, obstructive sleep apnoea; PedsQL, Paediatric Quality of Life Inventory; PGWBI, Psychological General Well-Being Index; PSQI, Pittsburgh Sleep Quality Index; RCT, randomised controlled trial; SE, sleep efficiency; SOL, sleep onset latency; TST, total sleep time.