Risk factors for long-term analgesic prescription after hip or knee arthroplasty for osteoarthritis: results of a multivariable regression analysis based on health insurance claims data from 137,875 patients with postoperative inpatient rehabilitatio

Abstract Background Continued analgesic prescription after elective total hip arthroplasty (THA) or total knee arthroplasty (TKA) indicates persistent pain and increases the risk of adverse drug reactions, particularly in older patients or those with chronic conditions. The aim of this study was to identify independent risk factors for long-term analgesic prescription in patients who have undergone arthroplasty followed by inpatient orthopaedic rehabilitation. Methods The study is based on nationwide claims data from Germany’s largest statutory health insurance provider (AOK) for the period from 2020 to 2024. Potential risk factors included demographic characteristics as well as factors related to the hospital stay/surgery and outpatient treatment in the 12 months prior to surgery. Adjusted odds ratios (OR) were calculated using a multivariable logistic regression model. In addition, we examined the extent to which model performance, measured by the area under the curve (AUC), improved when an additional variable category was included. Results The strongest association with long-term analgesic prescription after arthroplasty was observed for intensive use of analgesics in the year prior to surgery, which showed a more than sixfold increase in the odds (THA: OR 6.7; TKA: OR 7.5). A higher care dependency level, substance use disorders, a high BMI (≥ 40 kg/m 2 ), and various pain conditions showed significant associations, with adjusted ORs of up to 2.3 in both indications. Including risk factors from the 12-month pre-observation period into the regression model enhanced model performance strongly. Conclusion The results of this observational study based on a large nationwide database may provide valuable clinical insights and establish a robust framework for future confirmatory trials. Trial registration Not applicable. This study is a retrospective analysis of routinely collected billing data and does not involve health interventions.