Measuring the quality of life of cancer patients: the Functional Living Index-Cancer: development and validation.

The classical criteria for the evaluation of clinical trials in cancer reflect alterations in physical well-being, but are insensitive to other important factors, such as psychosocial state, sociability, and somatic sensation that may play a critical role in determining the patients' functional response to their illness and its treatment. The Functional Living Index-Cancer is designed for easy, repeated patient self-administration. It is a 22-item questionnaire that has been validated on 837 patients in two cities over a three-year period. Criteria for validity include stability of factor analysis, concurrent validation studies against the Karnofsky, Beck Depression, Spielberger State and Trait Anxiety, and Katz Activities of Daily Living scales, as well as the scaled version of The General Health Questionnaire and The McGill/ Melzack Pain Index. The index is uncontaminated by social desirability issues. The validation studies demonstrate the lack of correlation between traditional measures of patient response and other significant functional factors such as depression and anxiety (r = 0.33), sociability and family interaction, and nausea. These findings elucidate the frequently observed discrepancies between traditional assessments of clinical response and overall functional patient outcome. The index is proposed as an adjunct to clinical trials assessment and may provide additional patient functional information on which to analyse the outcome of clinical trials or offer specific advice to individual patients.