We would like to thank Prof. Meyer for his valuable comments on our article.
We agree that, besides reporting relative risks and hazard ratios, it is necessary to also report the absolute risk reduction (ARR) and the number needed to treat (NNT) to allow a clinical evaluation of treatment effects.
In our systematic review (1), we had to rely on information from the primary studies which was mostly inadequate for ARR/NNT, as for example in HYVET. Furthermore, NNT is strongly influenced by the baseline risk; thus, it cannot be considered a proper approach to compare NNT between the strata frail versus non-frail.
If one looks only at frail patients (frailty index >0.21) in the SPRINT study, one will find an absolute risk reduction (ARR) of 4.9% and an NNT of 20. Among non-frail patients, ARR was 3.3% with an NNT of 30.
At what point the difference between NNTs should be considered as relevant has to be discussed in the clinical context. As our primary aim was to compare the evidence for different treatments of arterial hypertension in frail versus non-frail older patients, calculation of NNT (or the “number needed to harm“ [NNH]) was not one of our main goals. Therefore, we presented the studies that had assessed effect modification by physical frailty. Unfortunately, however, the currently available data is not sufficient to warrant a differential treatment of arterial hypertension.
Prof. Dr. med. Michael Dieter Denkinger
PD Dr. med. Dhayana Dallmeier, Ph.D.
Geriatrie der Universität Ulm
and Geriatrisches Zentrum Ulm/Alb-Donau
Agaplesion Bethesda Klinik, Ulm, Germany
Conflict of interest statement
The authors of both contributions declare that no conflict of interest exists.
|1.||Mühlbauer V, Dallmeier D, Brefka S, Bollig C, Voigt-Radloff S, Denkinger M: The pharmacological treatment of arterial hypertension in frail, older patients—a systematic review. Dtsch Arztebl Int 2019; 116: 23–30 VOLLTEXT|