Disability Assessment medicine has achieved academic status through a Faculty of Occupational Medicine diploma and is a growing area of importance outside the OH Recruitment. We provide continuing medical education for staff and an environment geared towards professional development based on best practice.

However, it has recently been stated that simply modifying existing measures to enhance clinical evaluation may not be as useful as anticipated in improving the measurement properties of a scale (10). Thus, it is important that comparisons of such measures are undertaken to ensure that both clinical usefulness (aspects of the measure that concern implementation into clinical practice) and scientific soundness (assessment of reliability, validity and responsiveness) are evaluated (11,12).

Reliability considers whether a scale is consistent, produces accurate results, is stable over time, and is reproducible. Validity can be broadly defined as the extent to which a scale measures what it is intended to measure. Evidence for reliability however does not guarantee evidence for validity. Responsiveness is the ability of a scale to detect clinically significant change, and is closely related to validity. Each of these factors are important as the quality of outcome data is dependent on the quality of the scale employed. Scales that do not satisfy the above criteria may lead to inaccurate results which will have an impact on clinical decision making at the patient and population level (12,13).