Measuring disease-specific quality of life in clinical trials.

While measurement of quality of life is a vital part of assessing the effect of treatment in many clinical trials, a measure that is responsive to clinically important change is often unavailable. Investigators are therefore faced with the challenge of constructing an index for a specific condition or even for a single trial. There are several stages in the development and testing of a quality-of-life measure: selecting an initial item pool, …