One worry when the use of high quality adjusted existence years (QALY) to measure well being positive aspects for price effectiveness analysis is that QALYs “undervalue” well being positive aspects from existence extension for folks with critical sickness or persistent incapacity. To peer this obviously, check out the QALY components (first components beneath) and the way it may be decomposed into adjustments in high quality of existence (Q) and survival (S) for a brand new intervention (listed at 1) in comparison to the previous (listed to 0).
Observe that the survival positive aspects are simplest valued on the high quality of existence that the intervention can acheive (Q1t). Thus, survival enhancements for sufferers who stay having a deficient high quality of existence are devalued relative to people who woudl be in just right and even very best well being.
A paper by means of Campbell, Whittington and Pearson (2023) describes how the Institute for Scientific and Financial Overview (ICER) computes another measure: equivalent worth of existence years received (evLYG). I’ve described this means prior to now right here. evLYG can also be calculated as follows:
At the proper hand facet , the second one time period is the same in each the evLYG and QALY equations, indicating that high quality of existence positive aspects all the way through the survival duration of the primary particular person are evaluated the similar. Then again, below evLYG, survival positive aspects are valued at another quantity (Qt) which can also be other from the standard of existence worth of the brand new remedy. Underneath the unique evLYG means proposed by means of Nord et al. (1999), survival positive aspects are valued at very best well being (i.e., Qt=1). Then again, the Campbell et al. means utilized by ICER, units Qt=0.851, which is the same as the common application of the overall US grownup inhabitants. Observe that the ICER means assigns decrease evLYG than does the Nord means.
Underneath ICER’s implementation of evLYG, the other in the best way well being positive aspects are measured between evLYG and QALYs can also be summarized as follows:
evLYG have the important thing merit that survival positive aspects to sicker sufferers are valued extra (even supposing much less below ICER’s implementation than below Nord).
In truth, ICER’s evaluate of 32 distinctive interventions the use of each evLYG and QALY discovered that during 66% of circumstances ΔevLYG>ΔQALY, and in 34% of circumstances ΔevLYG=ΔQALY. The imply proportion alternate between an intervention dyad’s incremental QALYs and incremental evLYs was once 16%. Within the interventions the place ΔevLY > ΔQALY, incremental evLYs had been 25% upper than incremental QALYs.
One key limitation of evLYG is that high quality of existence enhancements all the way through the ‘survival achieve’ duration aren’t captured below evLYG.
You’ll learn the total paper right here. This is a helpful primer each on what evLYG is and the way ICER has been the use of evLYG in its checks.