Quality of life assessment: a comparison of four questionnaires: for measuring improvements after total hip replacement.

Three experimental questionnaires were compared with the Influence of Rheumatic Diseases on Health and Lifestyle (IRGL) questionnaire, a Dutch version of the Arthritis Impact Measurement Scales. Sixty-two patients with osteoarthritis (OA) and 35 patients with rheumatoid arthritis (RA), all of whom underwent hip arthroplasty, completed the study. Results showed that visual analogue scales for pain, stiffness, fatigue, and anxiety were strongly correlated with a number of the IRGL scales. Patient preference scales were sensitive to change and provided additional information on aspects of the patients' quality of life (QOL) that were felt to be important by the patients themselves. The questionnaire on performance in various roles in life was insensitive to change. In existing questionnaires, there is an attempt to represent the concept of QOL in terms of its most important aspects. Such realizations of the concept of QOL are not entirely suitable for application in clinical trials. The IRGL is overly complex, and its sometimes comprehensive scales do not deal with the possible effects of treatment. Neither of these properties is conducive to sensitivity to change. Visual analogue scales reduce the complexity. A simpler representation of QOL that can evaluate aspects relevant to treatment is recommended.