In recent decades the cost of oncology treatments has spiraled as the success rate of those interventions has risen; some experts have estimated the rise in the cost of chemotherapy drugs alone at as much as 15% per year over the last fifteen years. This has led to much debate about the effectiveness and value of such interventions. Physicians, health economists and drug developers are concerned about how to compare the life-prolonging and quality of life-enhancing properties of drugs.

The cost-effectiveness of drugs is measured using quality-adjusted life years (QALYs), where the value of each year of life gained is adjusted proportionally downwards as expected health-related quality of life decreases. Peter Ubel from Duke University, Durham, North Carolina, USA and his co-workers have now published a survey of oncologists in the US that asked them to estimate the cost-effectiveness (in terms of cost per QALY) of hypothetical new life-prolonging and quality-enhancing cancer drugs. Surveys were mailed to 1397 members of the American Society of Clinical Oncology, presenting them with two clinical scenarios involving patients with metastatic cancer. One of these concerned a drug that could extend life by months with no change in quality of life, and the other a drug that gave a significant improvement in quality of life but did not affect survival. The subjects were asked for the number of extra months' survival for which they would prescribe the first drug at an additional cost of $50,000; the highest extra cost at which they would be prepared to prescribe the second; basic attitudes and demographic information. A cost-effectiveness ratio was calculated for each subject and each drug, in the first case as yearly incremental cost of the drug divided by months of extra survival, and in the second as incremental cost of the drug divided by incremental increase in quality of life on a 0-100 scale.

Responses were received from 786 oncologists, giving a response rate of 58%. Three-quarters of responders were male, with a mean age of 50; there were no significant demographic differences between responders and non-responders. A significant majority of the oncologists endorsed a higher cost per QALY in the life-extending scenario, proving that they place a higher value on treatments that prolong life than on those that only improve its quality. These responses were compared with answers to an attitudinal question that asked the oncologists what range of treatment cost they thought as "reasonable" per QALY gained. Interestingly, many respondents endorsed costs for the life-prolonging drug that were significantly higher than their own self-reported "reasonable cost"; the costs endorsed for the quality-enhancing drug were within those limits. These reported differences were consistent across the whole sample, not depending on age, gender, experience or whether the clinicians felt that they were well prepared to make decisions based on cost-effectiveness.

Many experts believe that physicians should apply the same QALY thresholds to all treatments, and consistent QALY thresholds are imposed in some health systems, including the UK's National Institute for Health and Clinical Excellence (NICE). It is, therefore, interesting that – at least in this fairly small and simple study – oncologists seem to place different values on QALYs in different contexts. Physicians in general are becoming more familiar with cost-effectiveness analysis, which must be helpful. However, both oncologists and their patients have widely differing value-systems, and open discussion of issues may be more important than the imposition of firm cost-effectiveness criteria.

Reference:

Kozminski, M.A., Neumann, P.J., Nadler, E.S., Jankovic, A. and Ubel, P.A. (2010). How Long and How Well: Oncologists' Attitudes toward the Relative Value of Life-Prolonging v. Quality of Life-Enhancing Treatments. Medical Decision Making, published online ahead of print November 19, 2010.