A cross-sectional analysis of research waste in randomized controlled trials on postoperative cognitive dysfunction

Postoperative cognitive dysfunction (POCD) is a common postoperative complication in older adults, with high-quality evidence mainly from randomized controlled trials (RCTs). However, research heterogeneity in this field may lead to significant waste, yet a systematic assessment is lacking. To analyze characteristics of POCD-related RCTs, quantify research waste, and explore influencing factors. This cross-sectional study searched ClinicalTrials.gov to identify registered RCTs initiated since 2000 that involved adult surgical patients and assessed postoperative cognitive function as a primary or secondary outcome. We extracted trial characteristics and evaluated publication status, reporting quality, and risk of design flaws. Analyses included descriptive statistics, chi-square tests, and logistic regression. Among 53 included RCTs, trials were predominantly drug-based (94.34%), single-center (75.47%), and non-department funded (98.11%), with Asia being the largest contributing region (43.40%). Of 43 trials completed by 2023, only 7 (16.3%) were published, mostly from North America/Europe (P = 0.012). Reporting quality was good, but 42.9% had design flaws. Research waste reached 90.7% (39/43), and Asian-origin trials showed the highest waste rate (51.28%, P = 0.028). Regression suggested trends linking larger sample sizes/multicenter designs to lower waste and non-Western regions to higher waste/lower publication, but these were not statistically significant. In conclusion, POCD RCTs exhibit high research waste with notable geographic imbalance. Waste appears multifactorial. Enhancing methodological rigor and improving research translation mechanisms are needed to optimize resource use and evidence quality.