Citation Study Population Intervention Outcomes Sample size Compliance to Results & design level measured duration sodium target location of relevant to (urinary data) research question II Adults (aged All participants Blood pressure 418 4 weeks Low sodium diet: Mean difference (seated after 2 et al. 18-80 years), consumed a reduced 81.9 + between low min rest), 24 (1993), parallel salt diet for 2 weeks. 26.6mmol/24hr sodium diet and hr. ambulatory Spain design Participants were (NS) normal sodium BP (only in 61 study hypertension then randomised to diet: pts.) [] Normal sodium (DBP:90 one of two groups: – diet: 186.0 + SBP: (SEM: 114mmHg) 1. Low salt diet plus 36.3mmol/24hr 1.94, CI: -2.80, 4.80) slow release (p<0.001 DBP: 1.9mmHg verapamil once a day compared to low (SEM: 0.94, CI: salt run-in period) 2. Unrestricted salt 3.74) diet plus slow release verapamil once a day Key features for bias assessment of randomised trials Citation Method of Allocation Blinding Loss to Use of Ceasing Reporting all Funding source randomisation concealment early outcome results where for benefit required
Citation & location Study design level of Population Intervention Outcomes measured relevant to research question Sample size duration Compliance to sodium target (urinary data) Results et al. (1993), Spain [] parallel design study II Adults (aged 18-80 years), hypertension (DBP:90 – 114mmHg) All participants consumed a reduced salt diet for 2 weeks. Participants were then randomised to one of two groups: 1. Low salt diet plus slow release verapamil once a day 2. Unrestricted salt diet plus slow release verapamil once a day Blood pressure (seated after 2 min rest), 24 hr. ambulatory BP (only in 61 pts.) 418 4 weeks Low sodium diet: 81.9 + 26.6mmol/24hr (NS) Normal sodium diet: 186.0 + 36.3mmol/24hr (p<0.001 compared to low salt run-in period) Mean difference between low sodium diet and normal sodium diet: SBP: (SEM: 1.94, CI: -2.80, 4.80) DBP: 1.9mmHg (SEM: 0.94, CI: 3.74) Key features for bias assessment of randomised trials Citation Method of randomisation Allocation concealment Blinding Loss to Use of where required Ceasing early for benefit Reporting all outcome results Funding source