Outcome assessment: functional status measures and quality of life as therapeutic endpoints in oncology

There is now agreement among most authorities regarding the need for a global measure of outcome in cancer clinical trials and guarded enthusiasm for incorporation of these. The next step--selection of existing instruments or development of new ones--appears to represent the current state of affairs. There is an urgent need for additional research into the meaning of life and health that the diagnosis of cancer generates. There are obvious dangers in relying on scales that do not reflect the patient's perception of quality of life. A number of instruments are available, and some of these are adequate in selected contexts. Poor psychometric testing and absence of evidence of predictive validity of existing or newly developed instruments may be expected to lead to false negative findings, however, when the impact of treatments on quality of life are compared. Following instrument development will be the incorporation of questionnaires into study design, which will represent a large task for many individuals. And last, but probably most important, we will have to determine how the results of QOL trials will be interpreted. The first important step towards incorporation of QOL/functional status as outcome measures in cancer clinical trials has occurred. To reach this goal will undoubtedly require a positive commitment from both medical and research staffs.