Outcome measurement in clinical practice: practical and theoretical issues for health related quality of life (HRQOL) questionnaires

Abstract

The defining characteristic of clinical outcome measurement tools is that they are intended to measure change over time. There is a range of practical issues that must be considered when choosing outcome measures for routine use in the clinical setting. Outcome measures should be: relevant to patients’ values and perceived needs; measure aspects of health and function that are relevant to the treatment offered; have sound psychometric properties; be quick and easy to complete and score; and, be intuitive to interpret. They should also provide clinically meaningful information useful to the clinician for decision-making regarding patient care.Outcome measures fall broadly into two types: measures of impairment of physical structures or functions; and measures of activities or participation as determined by health-related quality of life (HRQOL) questionnaires. Whilst recognizing that measures of physical impairments have an important role in patient assessment, this paper focuses on HRQOL measures. It is intended as a summary of the key attributes of HRQOL outcome measurement tools. The different types of outcome measures are reviewed along with the important scientific and practical considerations for the choice of an outcome measure. The determination of validity, reliability, responsiveness for outcome measures is explained, and the interpretation of changes in score for an outcome measure in terms of minimal important difference is outlined.