Analysis of core outcome set reporting in coronary intervention trials

Background This paper will focus on outcome reporting within percutaneous coronary intervention (PCI) trials. A core outcome set (COS) is a standardised set of outcomes that are recommended to be reported in every clinical trial. Using a COS can help to ensure that all relevant outcomes are consistently reported across clinical trials. In 2018, the European Society of Cardiology outlined the only COS published for PCI trials. Methods We searched the literature for all randomised controlled trials published between 2014 and 2022. PCI trials included were late-phase trials and must investigate coronary intervention. The primary outcome was the proportion of trials that reported all of the COS-defined outcomes within their publication as either a primary, secondary or safety endpoint. The secondary outcomes included; the number of primary outcomes reported per study, the proportion of studies which use patient and public involvement (PPI) during trial design, outcome variability and outcome consistency. Results 9580 trials were screened and 115 studies met inclusion/exclusion criteria. Our study demonstrated that 55% (34/62) of PCI trials used a COS when it was available, compared with 40% (21/53) before the availability of a PCI COS set, p=0.121. Fewer primary outcomes were reported after the implementation of the COS, 2 compared with 2.3, p=0.014. There was no difference in the use of PPI between either group. There was a higher level of variability in outcomes reported before the availability of the COS, while the consistency of outcome reporting remained similar. Conclusion The use of a COS in PCI trials is low. This study provides evidence that there still is a lack of awareness of the COS among those who design clinical trials. We also presented the inconsistency and heterogenicity in reporting clinical trial outcomes. Finally, there was a clear lack of PPI utilisation in PCI trials. Data sharing not applicable as no data sets generated and/or analysed for this study.