What is the quality of the evidence for the important outcomes of eplerenone and spironolactone?
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).