Patient-reported outcome measures (PROMs) following knee arthroplasty: a prospective cohort study protocol

To evaluate the quality of clinical practice, patient-reported outcome measures (PROMs) are important as certain questions could only be answered by the patient himself. PROMs help to get a better understanding what is meaningful to a patient and directly affects daily functioning. To move beyond traditional measures, we are interested in what matters to patients and developed this project. The aim of this article is to provide the protocol for our study collecting PROMs in daily medical practice from patients who undergo knee arthroplasty.

This study is a single-site, observational, prospective cohort study. We will recruit patients scheduled for a knee arthroplasty in our medical office, situated in a private clinic. After signed informed consent, patients complete self-reported questionnaires before the surgery, after 4 months, 1 year, 2 years, 3 years, 4 years and 5 years. We will use the following PROMs: Knee injury and Osteoarthritis Outcome Score, Forgotten Joint Score, EuroQol five dimensions and satisfaction. Additionally, the surgeon will complete the objective Knee Society Score. Administration of the questionnaires will be electronically or paper-based. We will assess differences between preoperative and postoperative data with paired t-test for continuous variables and Wilcoxon signed-rank test for categorical variables. To assess subgroup differences, we will use unpaired t-test for continuous variables and Mann-Whitney U test for categorical variables. To assess possible presence of bias, we will conduct sensitivity analyses.

The study has been reviewed and approved by the local ethics committee in Basel, Switzerland. Written informed consent will be obtained from all patients. We will disseminate the results of the study through peer-reviewed journals, national and international conference presentations and presentations to relevant stakeholders through appropriate channels.