Hip and Knee Osteoarthritis : Who Are the Patients Referred to First-Line Intervention and What Happens to Them?

Sammanfattning: Background: First-line intervention to address osteoarthritis (OA) should include patient education, exercise therapy, and weight control if needed. Replacement surgery may be appropriate for patients who do not receive sufficient relief from non-surgical interventions. However, predicting the course of OA can be challenging. Some patients experience stable symptoms over time, while others may have a rapid increase in pain and functional impairment. This thesis aims to improve understanding of which patients are referred to first-line intervention for hip and knee OA and to identify factors that affect long-term outcomes in these patients.Methods: The thesis includes studies of patients with hip and knee OA referred to a standardized first-line intervention programme. Study A (papers I, II, IV, V) is a register-based observational study that uses the Swedish Osteoarthritis Register (SOAR) to identify an OA population (n = 72 069). Data from the SOAR was merged with data from the Swedish Arthroplasty Register, Statistics Sweden and the National Board of Health and Welfare. The study also includes a matched reference cohort (n = 216 207) from the general Swedish population for comparison. Papers I and II compare socioeconomic status (SES) and comorbidities of the OA population in the SOAR with the reference cohort. Study B (paper III) is a qualitative study involving 16 patients with hip and knee OA who expressed a desire for surgery at referral to first-line intervention. The study includes interviews regarding the patients’ perspectives on healthcare and self-management of OA. Paper IV examines the time to replacement surgery and prognostic factors for surgery in the OA population. Paper V identifies factors associated with poorer patient-reported outcomes 1 year after hip replacement surgery.Results: The OA population had higher SES and higher odds of having comorbidities than the reference cohort. The differences in comorbidities were greater in younger individuals and those with knee OA. Patients who expressed a desire for surgery before participating in first-line intervention described their perspectives on healthcare and self-management as a multifaceted picture of needs, expectations, and individual choices. Findings range from a passive approach towards managing the OA, described as a lack of control, a sense of being left alone by healthcare, having doubts and mistrusting the care provided, to a more active attitude manifested as a will to take control over the OA, instead of the OA taking control over the patient’s life. Of the patients registered in the SOAR, 46% with hip OA and 20% with knee OA were estimated to progress to replacement surgery within 5 years. The strongest prognostic factors were expressing a desire for surgery and having more severe OA symptoms. In addition, higher SES and the presence of comorbidities had an impact on the risk of progression to surgery. Among those who had undergone a hip replacement, 5%–11% showed poor patient-reported outcomes regarding pain, health-related quality of life, and satisfaction 1 year after surgery. Factors associated with poor outcomes were being older, classified as Charnley C (musculoskeletal comorbidities), or having several comorbidities, particularly depression.Conclusions: Higher SES in the OA population referred to first-line intervention than in the general population indicates that OA care in Sweden may not be equal. The higher prevalence of comorbidities in the OA population suggests that OA care should include improving overall health. Furthermore, first-line OA intervention should be tailored to each patient’s perspectives to achieve the lifestyle changes that the interventions strive to accomplish, especially in patients expressing a desire for surgery at referral. Patients with hip and knee OA differ in their progression to surgery. Those with hip OA tend to progress faster and undergo replacement surgery more often than those with knee OA. Expressing a desire for surgery and having severe OA symptoms are prognostic factors, but other non-OA-related factors play a significant role. However, a large proportion of patients with OA do not require surgery within 5 years after referral to first-line intervention, especially those with knee OA. Identifying depression at the stage of referral to first-line OA intervention would allow increased time to optimize treatments and may help improve patient-reported outcomes after surgery.