What are the critical outcomes for this review?
The committee considered quality of life and unplanned hospitalisation to be the critical outcomes for this review. Data on all-cause hospitalisation were considered preferable to data limited to heart failure (HF) related hospitalisations, as such data take into account the broader unintended consequences of the interventions (for example, an increase in hospitalisations due to adverse events). Change in appetite, weight and oedema, as well as impact on renal function and hyperkalaemia, were considered to be important for decision-making. For patients with low sodium levels at baseline, change in serum sodium level was also considered an important outcome. While serum sodium level is often reported as an outcome in sodium restriction studies, it was not considered clinically relevant for HF patients with normal baseline sodium. Also, while studies often report actual reductions in sodium and/or fluid intake after the delivery of a restriction intervention, again this was not considered to be a key clinically important outcome. Given the nature of the interventions in this review, mortality was not included as an outcome. The committee was more interested in the impact on symptoms and hospitalisation.