Evaluating research waste and traits among randomized controlled trials of scars over the past 20 years: a cross-sectional study.

Purpose: To analyze the changes in the characteristics of randomized controlled trials (RCTs) in the field of scarring over the last two decades, unveil the components of research waste (RW) within these RCTs, and identify targets for improvement.

Methods: A search was conducted on ClinicalTrials.gov for RCTs registered from January 2000 to December 2023, using "scar" as the keyword. The search was carried out in January 2024.

Results: 391 RCTs were included in this analysis. The global registration of RCTs in scarring has exhibited a consistent increase annually, with the proportion in Asia gradually rising, while the shares in North America and Europe have demonstrated a declining trend. In the analysis of RW, 232 RCTs were included, of which 96 (41.4%) have been published. Among the published RCTs, 56 (58.3%) were evaluated to have sufficient reporting, while 47 RCTs (48.9%) were identified as having avoidable design flaws. Ultimately, 183 RCTs (78.9%) exhibited at least one form of RW. Multicenter design (OR: 3.324, 95%CI: 1.385-7.975, P = 0.018), non-pharmacological interventions (OR: 2.61, 95%CI: 1.253-5.435, P = 0.010), the absence of external funding (OR: 0.325, 95%CI: 0.144-0.732, P = 0.031), and participant numbers exceeding 50 (OR: 3.269, 95%CI: 1.573-6.794, P = 0.002) were identified as independent protective factors against waste.

Conclusions: This study delineates the changes in the characteristics of scar RCTs globally over the past two decades, uncovering a substantial burden of RW in scarring research. It provides an evidential reference for more rational planning of future scar-related RCTs and for minimizing RW.