Socioeconomic status affects patient-reported outcome measures in total hip and knee arthroplasty: A retrospective Dutch registry study

Background To determine the association between socioeconomic status and patient-reported outcome measures in a Dutch cohort who have undergone total hip arthroplasty (THA) or total knee arthroplasty (TKA). Methods A retrospective national registry study of all patients who underwent primary THA or TKA between 2014-2020 in the Netherlands was performed. Linear mixed-effects regression models were used to assess the association between SES and PROMs for THA and TKA patients separately. The following measures were collected: Numeric pain rating scale, Oxford Hip/Knee Score, Hip/Knee disability and Osteoarthritis Outcome Score and the EuroQol 5-Dimensions-questionnaire. Sex, age, body mass index, American Society of Anesthesiologists-classification, Charnley-classification and smoking status were considered as covariates in the models. Results THA patients (n=97,443) were on average 70 years old with a BMI of 27.4 kg/m2, and TKA patients (n=78,811) were on average 69 years old with a BMI of 29.7 kg/m2. Preoperatively, patients with a lower socioeconomic status undergoing THA or TKA reported more severe symptoms and lower health-related quality of life. At 1-year follow-up, they also reported lower scores and less improvement over time compared to patients with a higher socioeconomic status. Conclusion Patients with lower socioeconomic status report worse symptoms when admitted for surgery, and less improvement after surgery. Future research must address potentially mediating factors of the association between socioeconomic status and symptom reporting such as access to surgery and rehabilitation, subjectivity in reporting, and patient expectation for THA and TKA outcomes.