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 Nevertheless, published studies predominantly had a sample size ≥ 100 patients (76%), in contrast to unpublished trials (p ≤ 0.001).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.