Measuring patient-reported physical function and pain in total hip and knee arthroplasty

Patient-Reported Outcome Measures (PROMs) are designed to capture patients’ perspectives in total hip arthroplasty (THA) and total knee arthroplasty (TKA). The recommended set of PROMs for patients undergoing THA and TKA have substantial limitations in their measurement properties and are often poorly implemented. Optimizing PROM selection and use is essential for improving patient-centered orthopedic care, research, and policy-making. The overarching aim of this thesis is to optimize the measurement of physical function and pain in THA and TKA patients using PROMs. Part I. Measurement properties of legacy PROMs evaluating physical function in THA and TKA This part comprises evaluates the psychometric properties of legacy PROMs measuring physical function in THA and TKA. A systematic review (Chapter 2) of the HOOS-PS and KOOS-PS revealed inconsistent and often insufficient evidence for content validity, suggesting that scores on the HOOS-PS and KOOS-PS may insufficiently reflect physical functioning. Furthermore, evidence for insufficient construct validity and responsiveness was found. Consequently, the use of the HOOS-PS and KOOS-PS for outcome comparison, evaluation of treatment effects, or benchmarking should only be done with great caution. A mixed method study (Chapter 3) assessed the content validity of the HOOS-PS. Only one of the five items was considered relevant for measuring physical functioning according to patients and experts. Comprehensiveness and comprehensibility were considered insufficient. Several items were found to be ambiguous or double-barreled. These findings challenge the applicability of the HOOS-PS in clinical practice, research, VBHC, and benchmarking. Part II: Towards an adequate alternative patient-reported outcome measure in THA and TKA In response to the limitations in Part 1, this part evaluates an innovative alternative: the Patient-Reported Outcomes Measurement Information System (PROMIS®). PROMIS is based on Item Response Theory, and enables the use of Computerized Adaptive Testing (CAT). In Chapter 4, the measurement properties of PROMIS and legacy instruments in patients undergoing THA were assessed. The PROMIS-PF was found to be less burdensome, with high measurement precision, almost no minimal or maximal scores, and equal reliability compared to legacy instruments. The PROMIS Pain Intensity 1a was found to be comparable to the legacy pain instruments in terms of burden, reliability, and SDC. The SDC values presented in this study can be used for individual patient monitoring. Chapter 5 assessed the psychometric properties of PROMIS measures compared to legacy PROMs. The results of this study showed that PROMIS measures seem more efficient for assessing patient-reported physical function in TKA, offering reduced burden and measurement error, and minimizing the occurrence of extreme scores. This can facilitate more accurate and patient-centered evaluations. Part III: Standardizing legacy PROM score conversions towards PROMIS scores This part evaluates existing crosswalks for converting legacy PROM scores in THA and TKA patients to PROMIS instruments. Chapter 6 validated existing crosswalks for transforming scores of the HOOS-PS, the KOOS-PS, and the KOOS-ADL subscale to the PROMIS Physical Function metric. This study concluded that these crosswalks towards PROMIS PF seem to be appropriate for group-level use but are not suitable for individual-level predictions of PROMIS scores. Discussion Key facilitators and barriers for PROM implementation in orthopedic care were identified using the Consolidated Framework for Implementation Research (CFIR). The transition to PROMIS could be part of the solution, due to its broad applicability, strong psychometric properties and better feasibility. Furthermore, effective integration of PROMs into clinical practice and VBHC frameworks, can facilitate remote monitoring and reduce low-value interventions. Patient, leader- and stakeholder engagement may optimize response rates and implementation. Implementing a standard set of PROMs that measure adequate what truly matters to THA and TKA patients can enhance shared decision-making, monitoring of treatment effectiveness, and more sustainable orthopedic healthcare.