The committee noted the higher risk of renal dysfunction for people taking MRAs. Renal dysfunction was not included in the Irish study, but was included in the UK study model. The committee considered that the associated cost in the UK economic analysis may have been underestimated due to the definitions adopted to report renal dysfunction in the EMPHASIS- HF trial, and believed that a significant proportion of these patients are likely to have had acute kidney injury (AKI) which incurs a higher cost than that adopted in the economic analysis. However, due to the negative effects that MRAs have on renal function the committee decided to recommend that blood monitoring should be undertaken during uptitration in the first 3 months, and then 6 monthly thereafter. This frequency of monitoring was previously suggested in the 2010 CHF guideline (CG108) Appendix D practical notes . Uptitration monitoring was a requirement of the EMPHASIS- Chronic Heart Failure Treating Heart Failure NICE 2018. All rights reserved. Subject to Notice of rights. ISBN: 978-1-4731-3093-7 HF clinical trial and therefore these costs were incorporated in the UK study. This consisted of 2 sets of blood tests and 2 hospital appointments with a consultant, and further monitoring costs were assumed to be the same as standard care. Although the committee recommend a couple more blood tests than were undertaken in the trial, this additional cost would be minor. In the Irish study, 1 extra outpatient visit for monitoring in the MRA arm compared to the standard care arm was assumed. The study also reports that even if 4 additional outpatient visits were assumed that spironolactone is still highly cost-effective. 