Measurement of quality of life in clinical trials.
Information on patients' quality of life (QOL) will give a more comprehensive evaluation of the treatment outcome than only measures of tumour response and survival. Psychosocial indicators have rarely been used in clinical trials. This may in part be explained by physicians' lack of familiarity with these measures, methodological insufficiency and a basic philosophical reason, i.e., most doctors tend to focus on curative treatment and not on palliative treatment. A series of QOL questionnaires has been validated in the last decade for use in cancer clinical trials. Selection of the optimal method in the given trial is important. The trial ought to be designed so the proportion of missing data is low. QOL should be used as an end point in selective trials with an optimal study design and with a study coordinator who is willing to collect QOL data.