Results reporting for clinical trials led by medical universities and university hospitals in the Nordic countries was often missing or delayed

Abstract Objective To systematically evaluate timely reporting of clinical trial results at medical universities and university hospitals in the Nordic countries. Study Design and Setting In this cross-sectional study, we included trials (regardless of intervention) registered in the EU Clinical Trials Registry and/or ClinicalTrials.gov, completed 2016-2019, and led by a university with medical faculty or university hospital in Denmark, Finland, Iceland, Norway, or Sweden. We identified summary results posted at the trial registries, and conducted systematic manual searches for results publications (e.g., journal articles, preprints). We present proportions with 95% confidence intervals (CI), and medians with interquartile range (IQR). Protocol: https://osf.io/wua3r Results Among 2,112 included clinical trials, 1,650 (78.1%, 95%CI 76.3-79.8%) reported any results during our follow-up; 1,097 (51.9%, 95%CI 49.8-54.1%) reported any results within 2 years of the global completion date; and 48 (2.3%, 95%CI 1.7-3.0%) posted summary results in the registry within 1 year. Median time from global completion date to results reporting was 690 days (IQR 1,103). 856/1,681 (50.9%) of ClinicalTrials.gov- registrations were prospective. Denmark contributed approximately half of all trials. Reporting performance varied widely between institutions. Conclusion Missing and delayed results reporting of academically led clinical trials is a pervasive problem in the Nordic countries. We relied on trial registry information, which can be incomplete. Institutions, funders, and policy makers need to support trial teams, ensure regulation adherence, and secure trial reporting before results are permanently lost. Plain language summary Reporting of results from clinical trials is necessary for evidence- based clinical decision making. We followed up reporting of clinical trials in the Nordic countries sponsored by medical universities and university hospitals. Of 2,112 studies completed 2016-2019 in two major trials registries, about half reported results in any form within 24 months and more than one in five did not report results at all. These results show that there is need for improvement in the reporting of Nordic clinical trials. What is new? - Many Nordic registered clinical trials were reported late or not at all. - Almost one in four trials remained unreported at the end of our search period. - About half of registered trials had reported results two years after completion. - Only 2.3% of trials posted summary results in the registry one year after completion. - Concerted action is needed to improve reporting of Nordic clinical trials.