Health outcome and quality-of-life measurements in amyotrophic lateral sclerosis.

Quality of life has been used as a primary outcome measure in the treatment of cancer and cardiovascular disease, and as a secondary outcome measure in therapy of Parkinson's disease. However, it has been relatively neglected in studies of amyotrophic lateral sclerosis (ALS). Although there is need for the development of an ALS-specific quality-of-life measure, it will be necessary, nonetheless, to continue to use generic measures in order to ensure comparability of measurement between disease states. An argument is put forward for the use of quality-of-life measures as a primary end-point in future clinical trials in ALS. A distinction is drawn between the demonstration of biological efficacy and clinically useful benefit. The most likely instruments to prove useful are briefly discussed.