Are quality of life, patient preferences, and costs realistic outcomes for clinical trials?

Health-related quality of life (HRQL) is a relatively new outcome, which is being considered for incorporation into randomized, controlled clinical trials. Instruments that detect different aspects of HRQL include health profiles and utility measurements. While the results of the former are highly responsive to change over time but not easily comparable between studies, utility measurements are not as responsive to change, but as single numerical values are more comparable between studies. With the growing number of multidimensional instruments available for measurement of the quality of life, investigators must be careful to select instruments that are reliable and have been validated for incorporation into clinical trials. Similarly, investigators must choose an instrument or instruments which are best suited to detection of the primary HRQL outcomes of interest for a specific population. A relatively new method for describing the quality of life during different health states is Q-TWiST analysis. An example is provided, demonstrating how the different short-term health states of patients with small cell lung cancer can be presented and quantified. While economic evaluation has often included quality of life within the concept of the quality-adjusted life year (QALY), determination of utilities within this concept has been highly variable and the validity of the QALY as a concept has been questioned. The health years equivalent (HYE) has been proposed as a more appropriate alternative. At the health policy decision-making level, controversy persists over how much society should pay for expansive new interventions and what boundaries for allocation should be established. Much work is still needed to improve comparability of HRQL results and to incorporate these results into clinical decision making involving individual patients and health policy makers.