Perez 1997.

Methods	Computerised randomisation Triple‐blind trial; outcomes assessed by blinded therapist Analysis by ITT No cross‐overs or losses to follow‐up 1 participant withdrawn with heart failure (nifedipine group) Baseline prognostic factors balanced between treatment groups
Participants	1 centre in UK 17 participants; 8 men Mean age 77 (SD 7) years All first ischaemic stroke 100% CT Enrolment 2 weeks after stroke
Interventions	Rx: nifedipine (30 mg orally daily, Bayer, UK) (n = 8) Pl: matching tablet; treatment for 4 weeks (n = 9)
Outcomes	Primary outcome: clinical improvement in swallowing Other outcomes: incidence of silent aspiration, pharyngeal transit time and response duration, swallowing delay (all assessed by videofluoroscopy), death
Notes	Exclusions: inability to sit, high clinical risk of aspiration, receptive dysphasia, cognitive impairment, pre‐stroke dysphagia, existing neurological or psychiatric disease, current treatment with calcium channel blockers or aminophylline Follow‐up: 4 weeks. 1 participant withdrawn with heart failure
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computerised randomisation
Allocation concealment (selection bias)	Unclear risk	Not stated
Blinding (performance bias and detection bias) All outcomes	Low risk	Triple‐blind trial
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Triple‐blind trial
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcomes assessed by blinded therapist
Incomplete outcome data (attrition bias) All outcomes	Low risk	1 participant withdrawn with heart failure (nifedipine group) No cross‐overs
Selective reporting (reporting bias)	Low risk	All outcomes reported
Other bias	Low risk	None identified