All RCTs started as High and the overall quality became Moderate, Low or Very Low if the overall score was 1, 2 or 3 points respectively. The significance of these overall ratings is explained in Table 4. The reasons for downgrading in each case were specified in the footnotes of the GRADE tables. Non-randomised intervention studies started at Low, and so a score of 1 would be enough to take the grade to the lowest level of Very Low. Non-randomised intervention studies could, however, be upgraded if there was a large magnitude of effect or a dose-response gradient. Table 4: Overall quality of outcome evidence in GRADE Level Description High Further research is very unlikely to change our confidence in the estimate of effect Moderate Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate Low Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate Very low Any estimate of effect is very uncertain 4.3.4.2 Prognostic reviews Risk of bias and applicability of evidence for prognostic risk data were evaluated per study using the Prediction study Risk of Bias Assessment Tool (PROBAST) draft checklist. Risk of bias and applicability were evaluated using of these 5 domains: Patient selection o appropriate data sources, inclusion and exclusion criteria and comparability of baseline values in the participants Chronic Heart Failure Methods NICE 2018. All rights reserved. Subject to Notice of rights. 