Outcomes
Pain, pain
MAY, DISEASES, EMERGENCY
We collected patient-reported outcomes from all participants at a single timepoint, at a median of four years after randomisation, starting from April 2021 to January 2023 (mean 3.91 years, range 3.42 to 4.44 years). A 22-month window for data collection was available for a range of 32 months of timepoints. The four-year timepoint (follow-up due after randomisation) was 25 October 2020 for the first participant to 31 May 2023 for the final participant.Outcomes collected in the trial were repeated for this four-year follow-up. The co-primary outcomes were self-reported pain severity and pain interference with daily living, measured by the Brief Pain Inventory (BPI) [Secondary outcomes were the: Oxford Knee Score (OKS) [Informatics Departments of the eight trial sites provided anonymised electronic hospital informatics coding data for each participant covering the period 12 to 48 months after randomisation. For inpatient stays and day cases, these included ICD10 (International Statistical Classification of Diseases), OPCS4 (International Classification of Interventions and Procedures), HRG (Health Resource Group) codes, admission and discharge dates. For outpatient visits, including procedures, radiology and Accident and Emergency attendances, data were obtained in the form of service codes, HRG/Currency codes and attendance dates.The outcome for the economic evaluation was the Quality-adjusted life year (QALY). The EQ-5D-5 L was used to calculate QALYs as it had been shown in the original study to be sensitive in relation to improvement overtime in both arms, confirming previous research [