On 2017 Oct 27, Andrea Messori commented:

                      .

THE ADVANTAGES OF NET MONETARY BENEFIT IN HANDLING MULTIPLE SIMULTANEOUS COMPARISONS .

A.Messori, HTA Unit, Regional Health Service, Firenze, Italy .

The paper by Trippoli [1] discusses the main advantages of net monetary benefit (NMB) in comparison with incremental cost-effectiveness ratio (ICER). There is however another important methodological advantage that deserves to be discussed in detail.

In the “classic” analyses based on ICER, only two comparators are directly managed. For example, if A is the innovative therapy and B is the standard therapy (and assuming that all values of cost and effectiveness are normalised to 1 patient), ICER is defined as follows: .  

Equation 1)    ICERAvsB  =  (costA - cost B) / (effectivenessA - effectivenessB)  <br>  <br>     .<br> After this calculation, ICERAvsB is evaluated against the pre-defined threshold (T) of cost-effectiveness (e.g.£ 30,000 in the UK or around $100,000 in the US) to decide if using A as opposed to B has a favourable cost-effectiveness (ICER<T) or an unfavourable cost-effectiveness (ICER>T).

In Western countries, the process of in-hospital procurement is often managed by running competitive tenders, particularly in the field of implantable medical devices. The problem is that, while tenders generally evaluate three or more comparators, the design of Equation 1 manages just a single comparison, i.e. two comparators only.

As pointed out by Trippoli [1], one important advantage of the NMB is that this parameter can be separately calculated for each of the (three or more) comparators under examination. Furthermore, these (three or more) values of NMB can then be compared with one another in any binary comparison and, finally, these values are expressed according to easily understandable units (represented by “differences in benefit”, where all benefits and all costs are expressed in monetary units normalized to 1 patient).

On the other hand, in the “classic” approach based on ICER the issue of comparing three or more comparators (e.g. four comparators named A, B, C, and D) is usually addressed by applying some methodological tricks. One of these tricks introduces ‘no treatment’ as a further comparator (although ‘no treatment’ is in some cases a reasonable comparator, but in other cases is not). Another one is to identify, as standard treatment (ST), a single comparator among A, B, C, and D (e.g. B so that ST=B), and to calculate ICERAvsST, ICERCvsST, and ICERDvsST; according to this latter solution, if ST=C, the calculation involves ICERAvsST, ICERBvsST, and ICERDvsST; if ST=D, the calculation involves ICERAvsST, ICERBvsST, and ICERCvsST; and so on. The drawback to all of this “classic” approaches is that the units of ICERs (ratio of incremental cost and incremental effectiveness) make their interpretation very difficult, and furthermore finding a role for T in this type of reasoning is difficult as well.

In conclusion, the NMB is much more efficient than the ICER in performing the simultaneous comparison of three or more comparators.

 <br> References

[1] Trippoli S. Incremental cost-effectiveness ratio and net monetary benefit: current use in pharmacoeconomics and future perspectives. Eur J Int Med 2017 Sep;43:e36.

On 2017 Oct 27, Andrea Messori commented:

                      .

THE ADVANTAGES OF NET MONETARY BENEFIT IN HANDLING MULTIPLE SIMULTANEOUS COMPARISONS .

A.Messori, HTA Unit, Regional Health Service, Firenze, Italy .

The paper by Trippoli [1] discusses the main advantages of net monetary benefit (NMB) in comparison with incremental cost-effectiveness ratio (ICER). There is however another important methodological advantage that deserves to be discussed in detail.

In the “classic” analyses based on ICER, only two comparators are directly managed. For example, if A is the innovative therapy and B is the standard therapy (and assuming that all values of cost and effectiveness are normalised to 1 patient), ICER is defined as follows: .  

Equation 1)    ICERAvsB  =  (costA - cost B) / (effectivenessA - effectivenessB)  <br>  <br>     .<br> After this calculation, ICERAvsB is evaluated against the pre-defined threshold (T) of cost-effectiveness (e.g.£ 30,000 in the UK or around $100,000 in the US) to decide if using A as opposed to B has a favourable cost-effectiveness (ICER<T) or an unfavourable cost-effectiveness (ICER>T).

In Western countries, the process of in-hospital procurement is often managed by running competitive tenders, particularly in the field of implantable medical devices. The problem is that, while tenders generally evaluate three or more comparators, the design of Equation 1 manages just a single comparison, i.e. two comparators only.

As pointed out by Trippoli [1], one important advantage of the NMB is that this parameter can be separately calculated for each of the (three or more) comparators under examination. Furthermore, these (three or more) values of NMB can then be compared with one another in any binary comparison and, finally, these values are expressed according to easily understandable units (represented by “differences in benefit”, where all benefits and all costs are expressed in monetary units normalized to 1 patient).

On the other hand, in the “classic” approach based on ICER the issue of comparing three or more comparators (e.g. four comparators named A, B, C, and D) is usually addressed by applying some methodological tricks. One of these tricks introduces ‘no treatment’ as a further comparator (although ‘no treatment’ is in some cases a reasonable comparator, but in other cases is not). Another one is to identify, as standard treatment (ST), a single comparator among A, B, C, and D (e.g. B so that ST=B), and to calculate ICERAvsST, ICERCvsST, and ICERDvsST; according to this latter solution, if ST=C, the calculation involves ICERAvsST, ICERBvsST, and ICERDvsST; if ST=D, the calculation involves ICERAvsST, ICERBvsST, and ICERCvsST; and so on. The drawback to all of this “classic” approaches is that the units of ICERs (ratio of incremental cost and incremental effectiveness) make their interpretation very difficult, and furthermore finding a role for T in this type of reasoning is difficult as well.

In conclusion, the NMB is much more efficient than the ICER in performing the simultaneous comparison of three or more comparators.

 <br> References

[1] Trippoli S. Incremental cost-effectiveness ratio and net monetary benefit: current use in pharmacoeconomics and future perspectives. Eur J Int Med 2017 Sep;43:e36.