Development of disease-specific quality of life measurement tools

Most of the conditions that physicians treat each day impact a patient's quality of life rather than the length or quantity of life. In orthopaedic surgery, traditional objective measures of patient outcome have included range of motion, strength, or radiographic variables. Although these measures have gained wide acceptance through their long-standing use, they are usually very poor indicators of the functional and psychological aspects of health. It makes sense to measure the phenomenon of health-related quality of life when assessing the relative efficacies of treatments that are available. If we can accept that health-related quality of life is important to measure, the next steps are to understand the types of instruments that are available and the appropriate methods by which these instruments should be developed and tested. Instruments fall into 2 general categories: generic or specific, each with specific advantages and disadvantages. The methodology for the development of quality of life tools emphasizes patient input and feedback. Determination of validity, reliability, and responsiveness in patients similar to those who will participate in trials is an important part of establishing the usefulness of an instrument.