Laub 2017.

Methods	Randomised controlled, parallel‐arm trial
Participants	POSA Participants randomised: 101 Inclusion criteria AHI supine ≥ twice AHI non‐supine AHI supine ≥ 10 AHI non‐supine < 10 10%‐90% sleep time in supine position Daytime tiredness and/or disturbed sleep and/or snoring Exclusion criteria Participant not able or willing to co‐operate Age < 18 years Central sleep apnoea Night work or shift work Clinical history of severe chronic heart failure or severe chronic obstructive pulmonary disease Medical history of other known causes of daytime tiredness or severe sleep disruption (insomnia, periodic leg movements, narcolepsy) Seizure disorder Known medical history of mental retardation, memory disorders or psychiatric disorders Inability to provide informed consent Implanted pacemaker Pain in hip or shoulder Unable to sleep in lateral positions Pregnancy or planned pregnancy in study period Breastfeeding women in study period Planned weight reduction in study period Planned smoking cessation in study period
Interventions	SPT, a vibrating supine alert device worn across participant's chest
Outcomes	Primary: short‐term efficacy and adherence of the SPT over a 2‐month period Secondary: long‐term efficacy and adherence of SPT for a 6‐month period
Notes	Funding: "Maribo Medicos A/S Denmark and Night Balance, the Netherlands provided the SPT devices free of charge. "The authors state that the study was an independent investigator‐initiated study Disclosure: "Philip Tonnesen has been a member of the steering committee for the annual sleep scientific meeting in Denmark arranged by Maribo Medico A/S"
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated list of random numbers was used for randomisation
Allocation concealment (selection bias)	Unclear risk	The exact procedure adapted for allocation concealment not mentioned
Blinding of participants and personnel (performance bias) Objective outcomes ( AHI)	High risk	Open‐label trial; no blinding
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Outcome assessor blinding not mentioned
Incomplete outcome data (attrition bias) All outcomes	High risk	26.7% of the participants dropped out before the first follow‐up at 2 months
Selective reporting (reporting bias)	Unclear risk	Protocol (NCT022114424) mentions similar outcomes to the report
Other bias	Unclear risk	None identified, except for the disclosure of the potential conflict of interest