Osteoarthritis impacts 7% of the global population, affecting more than 500 million people worldwide. As populations of OECD countries age, an increasing number of hip and knee replacement surgeries calls for further work on assessment of quality of care, particularly from patients’ point of view. Thirteen programmes from nine countries participated in the PaRIS Hip and Knee PROMs comparative reporting in 2020-21 by collecting and submitting data by generic and condition-specific PROMs. All programmes showed improvements in patient outcomes though the relative improvement varied. Crosswalks from SF-12 to EQ-5D provided valuable lessons on conversion errors. Results of this work call for improving the use of data for comparative reporting as well as further collaboration on utilising patient-reported metrics in quality-of-care improvement and policymaking.