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 nonanesthesiology clinical trials.

The Aggregate Analysis of ClinicalTrials.gov database was queried to identify anesthesiology and nonanesthesiology 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 nonanesthesiology trials were compared. Cochrane-Armitage trend tests were used to evaluate changes over time in characteristics of anesthesiology versus nonanesthesiology 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 (interquartile range) sample size for phase 3 or 4 anesthesiology and nonanesthesiology trials was 84 (52 to 120) and 90 (40 to 206) patients, respectively ( P < 0.0001). Trial duration was shorter for anesthesiology studies (median [interquartile range]): 15 (8 to 28) vs . 24 (12 to 44) months, respectively ( P < 0.0001). Globally, compared to nonanesthesiology trials, anesthesiology studies were seven times less likely to be sponsored by industry and two times less likely to be sponsored by government sources (4.5% vs . 32% and 6.0% vs . 12.7%, respectively). In the United States, 6.0% of anesthesiology trials and 18.9% of nonanesthesiology trials were federally funded, while industry funded 10.8% of anesthesiology trials and 43% of nonanesthesiology 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 this specialty's funding competitiveness.