Erturk 2013.

Study characteristics
Methods	Study design: parallel, RCT. Recruitment period: not available. Duration of study: not available. Study setting: outpatient. Hacettepe University Faculty of Physical Therapy and Rehabilitation Cardiopulmonary Rehabilitation Department, Turkey.
Participants	Key inclusion criteria: participants with mild, moderate and severe OSA who did not use CPAP, aged 19‐75 years. Key exclusion criteria: participants with a history of stroke, neurological disease, severe obstructive nasal disease and infection history in the last month, or BMI was 40 kg /m2 or more. Age (years): not available. Gender: not available. Comorbidities: not available. BMI: not available. AHI (events/hour): not available. ESS: not available. PSQI: not available. N randomised: 41: 15 in the IMT group, 14 in oropharyngeal exercises (OE) group and 12 in the control group. N analysed: 41. Dropouts: not reported.
Interventions	Intervention: oropharyngeal exercises. Same set of oropharyngeal exercises used by Guimaraes (see NCT00660777 Guimaraes 2009). 5 days a week for 3 months supervised by physical therapist. Used mirror for visual feedback. Comparators: Inspiratory muscle training. Not detailed. Standard medical treatment. Concomitant interventions: none
Outcomes	Prespecified outcomes: protocol not available. Reported outcomes: Anthropometric measurements (neck and abdominal circumference). Respiratory muscle strength (MIP, MEP). Exercise capacity (six minute walk test). Polysomnography recordings. Quality of life (FOSQ). Fatigue severity (FSS). Time points of measurement: before and 12 weeks after the treatment.
Notes	Publication: abstract from conference proceedings only. Additional information requested and received from authors on allocation procedures. Funding for trial: not reported. Conflicts of interest: none. Registered: not reported. Sample size calculations: not reported. Data sharing statement: none.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation with closed envelopes.
Allocation concealment (selection bias)	Low risk	Randomisation with closed envelopes.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Unblinded study.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Unblinded study.
Incomplete outcome data (attrition bias) All outcomes	Low risk	None declared.
Selective reporting (reporting bias)	Low risk	Protocol not available but they published outcome measurements relevant for the objectives of the study.
Other bias	Low risk	The study appears to be free of other sources of bias.