The Landscape of Anesthesiology Perioperative Interventional Clinical Trials Registered in ClinicalTrials.gov.

Although reports suggest that research productivity in anesthesiology has declined in recent decades, the actual specialty's efforts in clinical research are not well-known. The study aimed to describe characteristics and trends over time of anesthesiology-related and non-anesthesiology clinical trials. The Aggregate Analysis of ClinicalTrials.gov database was queried to identify anesthesiology and non-anesthesiology perioperative interventional clinical trials registered between 2008 and 2022. Trials were characterized based on study design, participant enrollment, duration, funding source, and geographic location. Anesthesiology trials were categorized according to eight areas of research. Characteristics of anesthesiology and non-anesthesiology trials were compared. Cochrane-Armitage trend tests were used to evaluate changes over time in characteristics of anesthesiology versus non-anesthesiology trials. Of 280,793 trials identified in the registry, 6,602 (2.4 %) were anesthesiology-related. The proportion of anesthesiology trials increased from 1.5% in 2008 to 2.7% in 2022 (p<0.001). Anesthesiology trials had smaller enrollment, and were more likely to be randomized, single-site studies (p< 0.001 for all). Median (IQR) sample size for phase 3/4 anesthesiology and non-anesthesiology trials was 84(52-120) and 90(40-206) patients, respectively; p<.0001). Trial duration was shorter for anesthesiology studies [median(IQR), 15(8-28) vs. 24(12-44) months, respectively; p<.0001]. Globally, compared to non-anesthesiology trials, anesthesiology studies were 7 times less likely to be sponsored by industry and 6 times less likely to be sponsored by government sources (4.5% vs. 32% and 6.0% vs. 12.7%, respectively). In the US, 6.0% of anesthesiology trials and 18.9% of non-anesthesiology trials were federally funded, while industry funded 10.8% of anesthesiology trials and 43% of non-anesthesiology trials. Most anesthesia trials were focused on regional (31.3%) or general (30.2%) anesthesia. Anesthesiology interventional trials are predominantly small, single-site, randomized studies sponsored by sources other than government or industry. Significant efforts are needed to design large multicenter clinical trials that enhance our specialty's funding competitiveness.