The evidence for eplerenone and spironolactone was analysed together for all outcomes except for gynaecomastia, where the 2 interventions were analysed separately due to gynaecomastia being a common adverse effect of spironolactone but an uncommon effect of eplerenone. Quality of the clinical evidence The evidence for the critical outcomes of all-cause mortality, all-cause hospitalisation and hospitalisation for any cause (dichotomous) was graded low to very low quality due to indirectness (the majority of the evidence was from a population not on beta-blockers), imprecision (based on the confidence intervals around the relative effect) and inconsistency (due to heterogeneity in the case of all-cause mortality caused by a study with a small sample size). However, the committee noted that for all-cause mortality and all-cause hospitalisation, the confidence intervals around the absolute effect were reasonably narrow and the committee was confident that in each case that there was a clinically important effect. The quality of the evidence for the important outcomes ranged from moderate to very low. For the adverse event of hyperkalaemia, the quality of the evidence was low, due to inconsistency and risk of bias which likely underestimated the incidence of hyperkalaemia (as the incidence of hyperkalaemia of 7 % was far exceeded by the rate of drug discontinuation of 17%). For deterioration in renal function, the quality of the evidence varied, with the majority of the evidence being of moderate quality, again due to risk of bias. The quality of the evidence for gynaecomastia was moderate for spironolactone due to risk of bias which likely underestimated the incidence of the event, and very low for eplerenone due to risk of bias and imprecision (though regarding the latter, the committee noted that there was no serious imprecision in the confidence intervals around the estimated absolute effect). 