asymmetry was used checked for were (<2g/day vs >2g/day, outcome, sodium to investigate heterogeneity by conducted in <1.2g/day vs > intake level in the publication bias. visual inspection and different ethnicities. 1.2g/day and reference group and Separate Cochran’s test. Assessment of reduction relative to the difference in were also Random effects heterogeneity was control), status of sodium intake level conducted in specific meta-regression was conducted using a anti-hypertensive between the reference sub-groupings, used to assess the chi-squared test medication, duration, and comparison including effects of different included in the forest study design, type of group. pressure status factors such as initial plot. Funnel plots blood pressure device Sensitivity analyses (hypertensive or SBP, ethnicity and were assessed for used and method for were also conducted. normotensive), sex etc. asymmetry. measuring blood ethnicity and sex. Sensitivity analyses Sensitivity analysis pressure. were also conducted was performed Sensitivity analysis to assess the excluding studies conducted. robustness of the data giving rise to asymmetry in the funnel plots Critical Summary tables were Quality assessment of - Summaries of key - Summaries of key - Summaries of key Rating system not created, including studies took into points and data for points and relevant points and relevant used for individual appraisal system relevant statistics account each study were data for each study data for each study studies (due to broad which could be used randomisation made by reviewers were made by were made by range of study in the pooled procedure, - Risk of bias reviewers reviewers designs and sodium analysis. The risk of allocation evaluation conducted - Risk of bias - Risk of bias intake assessments) bias in included concealment, (see below) evaluation included evaluation included Summary tables were studies was evaluated blinding of - GRADE system not (see below) (see below) developed to present (see below). participants, used - GRADE - methodology details of The quality of the providers methodology used to used to assess the designs, which were evidence for the of care and outcome assess the quality of quality of the body of critically evaluated effect of salt assessors and losses the body of evidence evidence based on reduction on blood to follow (using methodological pressure was assessed Cochrane Reviewer’s appropriateness, using GRADE Handbook relevance of study (ranked separately for methodology) population, all participants, - GRADE system not interventions and used outcome measures
asymmetry was used to investigate publication bias. Separate were also conducted in specific sub-groupings, including pressure status (hypertensive or normotensive), ethnicity and sex. checked for heterogeneity by visual inspection and Cochran’s test. Random effects meta-regression was used to assess the effects of different factors such as initial SBP, ethnicity and sex etc. Sensitivity analyses were also conducted to assess the robustness of the data were conducted in different ethnicities. Assessment of heterogeneity was conducted using a chi-squared test included in the forest plot. Funnel plots were assessed for asymmetry. Sensitivity analysis was performed excluding studies giving rise to asymmetry in the funnel plots (<2g/day vs >2g/day, <1.2g/day vs > 1.2g/day and reduction relative to control), status of anti-hypertensive medication, duration, study design, type of blood pressure device used and method for measuring blood pressure. Sensitivity analysis conducted. outcome, sodium intake level in the reference group and the difference in sodium intake level between the reference and comparison group. Sensitivity analyses were also conducted. Critical appraisal system Summary tables were created, including relevant statistics which could be used in the pooled analysis. The risk of bias in included studies was evaluated (see below). The quality of the evidence for the effect of salt reduction on blood pressure was assessed using GRADE (ranked separately for all participants, Quality assessment of studies took into account randomisation procedure, allocation concealment, blinding of participants, providers of care and outcome assessors and losses to follow (using Cochrane Reviewer’s Handbook methodology) - GRADE system not used - Summaries of key points and data for each study were made by reviewers - Risk of bias evaluation conducted (see below) - GRADE system not used - Summaries of key points and relevant data for each study were made by reviewers - Risk of bias evaluation included (see below) - GRADE methodology used to assess the quality of the body of evidence - Summaries of key points and relevant data for each study were made by reviewers - Risk of bias evaluation included (see below) - methodology used to assess the quality of the body of evidence Rating system not used for individual studies (due to broad range of study designs and sodium intake assessments) Summary tables were developed to present details of designs, which were critically evaluated based on methodological appropriateness, relevance of study population, interventions and outcome measures
Sodium%20Supporting%20Document%201%20%20Systematic%20Literature%20Review.docx