Regina Bendrik: Aspects of improving and maintaining physical activity in patients with hip or knee osteoarthritis

Abstract

Aim: This thesis aims to enhance knowledge of how people with osteoarthritis should be managed and supported in order to increase and maintain physical activity in the long-term. 

Method: Study I and study II was based on a randomised controlled study (RCT) including 141 osteoarthritis patients. The short and long-term effect of an individualised physical activity on prescription intervention compared with individualised advice about physical activity were evaluated. The primary outcome was physical activity and secondary outcomes were fitness/performance, pain and quality of life, evaluated at 6, 12 and 24 months. In Study III, 7-day diaries were evaluated regarding which forms of physical activity i.e. walking, swimming, cycling, gardening etc. the patients chose themselves and maintained after one and two years. In addition were evaluated, which category these activities belonged to: aerobic, muscle strength, mind-body or everyday activity, and whether there were differences in characteristic of the patients in the different forms. In study IV responsiveness of function, how well instruments captured an improvement, one year after a physical activity intervention was measured. Two unilateral performance-based tests were compared with a bilateral performance-based test and with questionnaires about function. 

Results: The RCT provided no evidence that individualised physical activity on prescription differ from individualised advice on physical activity in improving short and long-term physical activity, function, pain and quality of life (Study I and II). Walking was the form of physical activity performed most frequently and best maintained after 12 and 24 months. Walking were preferred by women, older individuals and individuals with weak legs while men also preferred everyday activity and cycling. Few patients preferred strength training (Study III). The maximal step-up test (one-leg testing) was more responsive to change in physical function (SMD effect size 0.57) compare to the bilateral 30-second chair-stand test (0.48) (Study IV). 

Conclusion: There is still absence of evidence for any particular physical activity intervention to effectively increase physical activity in the long-term in osteoarthritis patients. Individual counselling with support to choose preferred physical activities that are easy to perform in daily life may be a beneficial approach for long-term maintenance.