Protocol for a multicenter study on effectiveness and economics of the Back At work After Surgery (BAAS): a clinical pathway for knee arthroplasty

BackgroundOptimizing return to work (RTW) after knee arthroplasty (KA) is becoming increasingly important due to a growing incidence of KA and poor RTW outcomes after KA. We developed the Back At work After Surgery (BAAS) clinical pathway for optimized RTW after KA. Since the effectiveness and cost analysis of the BAAS clinical pathway are still unknown, analysis on effectiveness and costs of BAAS is imperative.Method This protocol paper has been written in line with the standards of Standard Protocol Items: Recommendations for Interventional Trails. To assess the effectiveness and cost-effectiveness for RTW, we will perform a multicenter prospective cohort study with patients who decided to receive a total KA (TKA) or an unicompartmental KA (UKA). To evaluate the effectiveness of BAAS regarding RTW, a comparison to usual care will be made using individual patient data on RTW from prospectively performed cohort studies in the Netherlands.Discussion One of the strengths of this study is that the feasibility for the BAAS clinical pathway was tested at first hand. Also, we will use validated questionnaires and functional tests to assess the patient's recovery using robust outcomes. Moreover, the intervention was performed in two hospitals serving the targeted patient group and to reduce selection bias and improve generalizability. The limitations of this study protocol are that the lead author has an active role as a medical case manager (MCM) in one of the hospitals. Additionally, we will use the data from other prospective Dutch cohort studies to compare our findings regarding RTW to usual care. Since we will not perform an RCT, we will use propensity analysis to reduce the bias due to possible differences between these cohorts.Trail RegistrationThis study was retrospectively registered at clinicaltrails.gov (, date of first registration: 19-01-2023).