A weighted average score was then calculated across all studies contributing to the outcome by taking into account study precision. For example, if the most precise studies tended to have an indirectness score of 1 each for that outcome, the overall score for that outcome would tend towards 1. Inconsistency refers to an unexplained heterogeneity of results for an outcome across different studies. When estimates of the treatment effect across studies differ widely, this suggests true differences in the underlying treatment effect, which may be due to differences in populations, settings or doses. When heterogeneity existed within an outcome (chi-squared p<0.1, or I2 no plausible explanation could be found, the quality of evidence for that outcome was downgraded. Inconsistency for that outcome was given a serious score of 1 if the I2 was 50 74%, and a very serious score of 2 if the I2 was 75% or more. If inconsistency could be explained based on prespecified subgroup analysis (that is, each subgroup had an I2 <50%), the committee took this into account and considered whether to make separate recommendations on new outcomes based on the subgroups defined by the assumed explanatory Chronic Heart Failure Methods NICE 2018. All rights reserved. Subject to Notice of rights. ISBN: 978-1-4731-3093-7 factors. In such a situation the quality of evidence was not downgraded for those emergent outcomes. Since the inconsistency score was based on the meta-analysis results, the score represented the whole outcome and so weighted averaging across studies was not necessary. The criteria applied for imprecision were based on the 95% CIs for the pooled estimate of effect, and the minimal important differences (MID) for the outcome. 