QALYs: the best option so far

I would like to challenge Maurice McGregor's argument in a recent commentary1 that because the quality- adjusted life-year (QALY) has “severe limitations,” it is not useful for cost-utility analyses.

To support his argument that the QALY is not meaningful, McGregor quotes a seminal work emphasizing the difficulty of using a single measurement to evaluate different health outcomes.2 However, this same text recommends the continued use of the QALY while researchers develop potentially better tools.2

McGregor also argues that the QALY is not valid because it “frequently violates societal concerns for fairness in the allocation of health care resources.” Such ethical concerns have been expressed before, but alternatives to circumvent them are still relatively nascent, and “the conventional QALY remains the dominant approach.”2

McGregor then contends that the QALY is not reliable because utility estimates vary with the method used. However, variability can occur in any research. Consider how frequently clinical studies yield conflicting results. A more pertinent question is whether this variability is truly fatal to interpreting cost-effectiveness analyses.

McGregor next argues that the QALY is not relevant because there is “no unanimity as to whose viewpoint should be used when making societal policy decisions.” This does not make the QALY irrelevant — it merely means that research is needed to clarify the issue.

McGregor's final argument is more a general cautionary statement: “When the studies with which the cost–utility analysis in question can be compared are not identified, the cost–utility analysis should clearly not be used in health policy decisions.” However, the same can be said in any field: comparators should always be identified. Furthermore, comparing one cost-effectiveness ratio with another is no different from using league tables based on number-needed-to-treat to evaluate the clinical effectiveness of interventions.3

Without doubt, the QALY is an imperfect outcome measure. Nonetheless, despite acknowledging its weaknesses, the 1996 Panel on Cost-effectiveness in Health and Medicine endorsed its use.4 Reporting “outcomes in natural units,” as McGregor suggests, detracts from the goal of developing an ideal measure incorporating both quantity and quality of life.

Christopher A.K.Y. Chong 4th-Year Medical Student Faculty of Medicine University of Toronto Toronto, Ont.