Phase III/IV trials of COPD maintenance management assess heterogeneous outcomes

<bold>Background:</bold> To inform guidelines and clinical practice, randomised controlled trials (RCTs) of COPD management need to address the outcomes that are most important to patients and health professionals. We surveyed the outcomes assessed in trials conducted since 2010. <bold>Methods:</bold> In this prospectively registered systematic review (PROSPERO: CRD42023466048), we assessed the outcomes reported in phase III/IV RCTs testing the efficacy and/or safety of pharmacological and non-pharmacological interventions for maintenance management of stable COPD. We sourced relevant trials registered between 2010-2023 on ClinicalTrials.gov. Two investigators independently screened each trial to determine eligibility and extracted the outcomes assessed in each included RCT. <bold>Results:</bold> We identified 225 RCTs, including 89 phase IV studies. 103 (46%) were completed with published results. Most included studies (88%) assessed pharmacological interventions and 62% were sponsored by the pharmaceutical industry. We identified 43 distinct outcome domains. The most frequently reported outcome was lung function (79%), followed by health-related quality of life (59%), symptoms (50%) and COPD exacerbations (41%). Lung function and COPD exacerbations were the most widely adopted primary outcomes (55% and 20%, respectively). Safety outcomes were reported in 37% of studies. Some of the outcomes prioritised in the ERS COPD exacerbations core outcome set were only infrequently assessed: Mortality (18%), Activities of daily living (6%). <bold>Conclusion:</bold> Phase III/IV trials on COPD management have heterogeneous outcomes, frequently omitting patient important outcomes. There is a need for a core outcome set to improve the design and value of RCTs.