STEPS 2016.

Methods	Computerised randomisation Single‐blind; outcome assessor blinded Analysis by ITT Baseline characteristics balanced
Participants	International, multi‐centre trial 162 participants; 94 men Mean age 74.4 years Dysphagia identified clinically and by videofluoroscopy
Interventions	Rx: active pharyngeal electrical stimulation C: sham pharyngeal electrical stimulation Follow‐up: up to 12 weeks
Outcomes	Primary: change in PAS at 2 weeks from baseline Secondary: safety outcomes, clinical dysphagia (Dysphagia Severity Rating Scale, PAS at 12 weeks), dependency (mRS), activities of daily living/disability (BI), impairment (NIHSS), health‐related quality of life (European Quality of Life‐5 Dimensions (EQ‐5D), nutritional measures (weight, mid‐arm circumference, and blood albumin))
Notes	Exclusions: history of dysphagia, dysphagia from a condition other than stroke, advanced dementia, implanted pacemaker or cardiac defibrillator in situ, unstable cardiopulmonary status or a condition that compromised cardiac or respiratory status, distorted oropharyngeal anatomy, additional diagnosis of progressive neurological disorder, receiving continuous oxygen treatment, pregnant or nursing mother
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation by computer‐generated permuted blocks
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding (performance bias and detection bias) All outcomes	Low risk	Researcher delivering the intervention not blinded
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Assessor and participant blinded
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessors blinded
Incomplete outcome data (attrition bias) All outcomes	High risk	181 participants randomised; only 123 participants completed all 3 treatments
Selective reporting (reporting bias)	Low risk	All outcomes reported
Other bias	Low risk	None identified