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. ISBN: 978-1-4731-3093-7 Predictors o Defined and assessed same way for all participants, blinding to outcome data,all relevant predictors analysed Outcome o Pre specified definition, predictors excluded from the outcome definition, outcome defined and determined in a similar way for all participants, blinding to predictor information Sample size and participant flow o Adequate number of outcome events, time interval between predictor assessment and outcome , appropriate missing data handling Analysis o non-binary predictors handled appropriately, univariable analysis avoided, model overfitting accounted for, complexities in the data (e.g. competing risks,) accounted for, assigned weights to predictors match the results from multivariable analysis, relevant performance measures are evaluated, e.g. calibration, discrimination, recalibrated if needed If data were meta-analysed, the quality for pooled studies was presented. If the data were not pooled, then the quality rating was presented for each study. Inconsistency was assessed as for intervention studies. Imprecision was assessed according to the range of point estimates of the primary measure. The evidence was downgraded by 1 increment when there was more than 20% range of the confidence interval around the point estimate and downgraded by 2 increments when there was a range of more than 40%. Imprecision was not estimable where studies did not report confidence intervals. 4.3.4.2.3 Overall grading Quality rating started at High for prospective and retrospective studies, and each major limitation brought the rating down by 1 increment to a minimum grade of Very Low, as explained for interventional reviews. 