Factors associated with poor self-reported function and quality of life in patients with end-stage knee or hip osteoarthritis immediately prior to total joint arthroplasty

INTRODUCTION: The aim was to evaluate patients’ perception of function and physical and mental dimensions of health-related quality of life (HRQoL) in patients with end-stage knee or hip osteoarthritis (OA) immediately prior to surgery and to identify the factors associated with the outcomes. MATERIAL AND METHODS: The study included 200 patients with end-stage OA (100 knee OA and 100 hip OA patients). Self-reported physical function was assessed using the Oxford Knee Score or Oxford Hip Score. Physical and mental dimensions of HRQoL were assessed using the physical and mental component summary scores of the 36-Item Short-Form Health Survey. Multivariate linear regression analysis was used to identify the sociodemographic, clinical and psychological factors associated with self-reported function and physical and mental dimensions of HRQoL. RESULTS: End-stage knee or hip OA patients had poor function and physical dimension of HRQoL, while the mental dimension of HRQoL was not impaired. In knee OA, pain, flexion range of motion (ROM), catastrophizing, and anxiety were significantly associated with self-reported function (explained 56% of the variance), whereas catastrophizing explained 10% of the variance of the physical dimension of HRQoL. In hip OA, flexion ROM, catastrophizing and being employed were significantly associated with self-reported function (explained 44% of the variance), whereas catastrophizing and flexion ROM explained 34% of the variance of the physical dimension of HRQoL. CONCLUSIONS: Many investigated factors were associated with poor self-reported function and HRQoL in knee and hip OA. However, the most important factors for both knee and hip OA were catastrophizing and flexion ROM.