Inclusion criteria

Types of participants

This review will consider studies that include adult patients (18 years or older) with heart failure, regardless of gender or ethnicity. Studies including children or pregnant women were excluded.

Types of intervention(s)/phenomena of interest

This review will consider studies that evaluate reduced dietary salt intake in patients with heart failure. The comparators include usual dietary salt intake, control or placebo diet, or no intervention.

Types of outcomes

This review will consider studies that evaluate reduced dietary salt intake in patients with heart failure and the outcome will be cardiovascular morbidity and cardiovascular-related hospital admissions.

Types of studies

This review will consider any experimental study design including randomized controlled trials, non-randomized controlled trials, quasi-experimental and before and after studies for inclusion.

Search strategy

The search strategy aims to find both published and unpublished studies. A three-step search strategy will be utilized in this review. An initial limited search of PubMed and CINAHL were undertaken, followed by analysis of the text words contained in the title and abstract and of the index terms used to describe the article. A second search using all identified keywords and index terms will then be undertaken across all included databases. Thirdly, the reference lists of all identified reports and articles will be searched for additional studies, as well as citation searches will be applied. Studies published in English, German, Danish, Swedish and Norwegian will be considered for inclusion in this review. Databases will be searched from their inception to September 2013 and the selected studies will be considered for inclusion in this review.

The databases to be searched include:

PubMed, CINAHL, Embase, Scopus, Swemed+, Health Technology Assessment Database, Turning

Research Into Practice (TRIP) Database

Additional searching for published literature will include:

Hand searching the reference lists and bibliographies of included articles and any relevant systematic

reviews identified in the Joanna Briggs Institute Library of Systematic Reviews and Cochrane Database

of Systematic Reviews

The search for unpublished studies will include searches of the following databases and websites:

- MedNar

- Sigle

- ProQuest Dissertations and Theses (for international dissertations and theses)

- National Institutes of Health (NIH) Clinical Trials Databases

(Host: NIH(http//clinicaltrials.gov))

- College of Nurses of Ontario (http://www.cno.org/learn-about-standards-guidelines)

- Heart failure relevant web sites

Initial keywords to be used include:

dietary salt intake, heart failure, readmission

Assessment of methodological quality

Papers selected for retrieval will be assessed by two independent reviewers for methodological validity prior to inclusion in the review, using standardized critical appraisal instruments from the Joanna Briggs Institute Meta Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI) (Appendix V). Any disagreements that arise between the reviewers will be resolved through discussion, or with a third reviewer.

Data collection

Data will be extracted from the papers included in the review using the standardized data extraction tool from JBI-MAStARI (Appendix VI). The data extracted will include specific details about the interventions, populations, study methods and outcomes of significance to the review question and specific objectives. Data extraction will be compiled by a single reviewer and checked by a second. Authors will be contacted where possible to obtain missing information.

Data synthesis

Quantitative data will, where possible, be pooled in statistical meta-analysis using JBI-MAStARI. All results will be subject to double data entry. Effect sizes expressed as odds ratios (for categorical data) and weighted mean differences (for continuous data) and their 95% confidence intervals will be calculated for analysis. Heterogeneity will be assessed statistically using the standard chi-square test. Where statistical pooling is not possible, the findings will be presented in narrative form including tables and figures to aid in data presentation where appropriate.

Conflicts of interest

None

Acknowledgements

None

References