PharmacoEconomics & Outcomes News 75 - 17 Aug 1996

Healthy-years-equivalents: the pros and cons

Critics of the concept of healthy-years equivalents (HYEs) suggest that health economic researchers should not throw away their 'QALY counters' just yet, claim Dr Milton Weinstein from the Harvard School of Public Health in Boston, US, and Dr Joseph Pliskin from Ben­Gurion University of the Negev in Beer-Sheva, lsrael.1

Against HYEs Criticisms of the HYEs concept, as indicated by Drs

Milton and Pliskin and Professor Peter Wakker from the University of Leiden in The Netherlands, include the followingY

• The theory is not new, but a generalisation of quality-adjusted life-years (QALYs).

• Utility assessment techniques proposed by the developers of HYEs are overly complicated and utility values are not easily interpreted.

• HYEs do not reflect attitudes towards risk and uncertainty as the developers claim; therefore, they cannot 'fully represent individuals' preferences', notes Dr Wakker.

• HYEs are inappropriate for use in real-world decision analyses, particularly those that involve Markov models.

In defence of HYEs Drs A Mehrez and A Gafni, the developers of HYEs,

emphasise that the concept is a generalisation of QALYs that allows decision makers more flexibility in assigning numbers of QALYs to health profiles. 3 They believe that researchers need to decide whether they want to avoid oversimplifying assumptions and focus on the challenges associated with use of more complex measurement techniques, or whether they want to remain where they are. They believe that 'the concept of the HYE represents a step in the right direction'.

Some common ground Dr Wakker and Dr Gafni agree that HYEs are a useful

tool to communicate expected utility values to nonspecialists, such as patients.23 They also concur that the increased flexibility and generalisation associated with a utility index like HYEs, must be offset by less specific predictions and prescriptions.4

Dr Wakker hopes that the debates surrounding the use of HYEs have increased people's awareness of the problems in measuring health outcomes.4

I. Weinstein MC, ct al. Perspectives on healthy-years equivalents: HYEs: what arc the issues'> Medical Decision Making 16: 205-206, Jui-Sep 1990.

2. Wakkcr P. A criticism of healthy-years equivalents. Medical Decision Making 16: 207-214, Jul-Scp 1996.

3. Gaffni A. HYEs: do we need them and can they fulfill the promise'' Medical Decision Making 16:215-216, Jul-Scp 1996.

4. Wakkcr P. HYEs: rejoinder. Medical Decision Making 16: 216, Jul-Scp 1996. lW04.'iRO.'iO