Characteristics of Out-of-Hospital Cardiac Arrest Trials Registered in ClinicalTrials.gov

Background/Objective: Out-of-hospital cardiac arrest (OHCA) poses a substantial public health concern. A collective evaluation of clinical trials is crucial for understanding systemic trends and progress within a specific research area of interest, ultimately shaping future directions. We performed a comprehensive analysis of the characteristics of trials in the adult OHCA population registered on ClinicalTrials.gov. Methods: Aided by medical subject headings (MeSH), we systematically searched the ClinicalTrials.gov database. Trends over time were assessed with the Cochran-Mantel-Haenszel test. The association between publication year and annual number was assessed with the Pearson correlation coefficient. Results: Out of 152 trials spanning the 2003-2023 period, 29.6% were observational and 70.4% were interventional. Compared with the observational trials, interventional trials were more often randomized (RCT) and achieved full publication status in 84% of cases (p = 0.03). The primary focus of interventional trials was "procedures" (43%), "devices" (23%), and "drugs" (21%). Observational studies focused on "biomarkers" (16%) and "diagnostic test" (13%) (p < 0.001). A decrement in the number of interventional trials with a sample size ≥100 patients across three temporal study points was observed. Nevertheless, published studies predominantly had a sample size ≥100 patients (76%), in contrast to unpublished trials (p ≤ 0.001). An increase in the number of interventional studies funded by the "academic/university" sector was also recorded. Conclusions: Clinical trials on OHCA primarily involved interventions aimed at treatment and were more often randomized, single-center, with small (<100) sample sizes, and funded by the "academic/university" sector.