The measurement of disability by means of summed ADL indices.

The characteristics of ADL indices which provide a total score of disability or capability are described, and the complexity of their rationale is stressed. The technical requirements of a good index in terms of reproducibility and validity are then discussed. It is suggested: (i) that there are some good validated indices available which, within limits, provide reproducible scores; (ii) that until demonstrably better indices are available, more suited to the local national context, workers should use these indices when they need total scores, in preference to devising their own.