Ethical and Linguistic Quality of Participant Information Sheets and Their Association with Recruitment Outcomes : An Empirical Bioethics Study of Clinical Trials.

Informed consent protects autonomy in clinical research, and it is often assumed that clearer Participant Information Sheets and Informed Consent Forms may also improve recruitment. This study examined whether the ethical and linguistic qualities of these documents are associated with accrual-related outcomes in industry-sponsored interventional trials. We conducted a retrospective analysis of ClinicalTrials.gov records with readable consent materials, operationalizing ethical clarity, linguistic comprehensibility, and cognitive burden using large language model-based extraction and quantitative text analysis. These measures were linked with trial status, enrolment, and operational duration. Across multinomial, binary, and competing risk models, none of the consent quality indicators predicted termination for poor accrual. Structural factors, particularly start year and enrolment capacity, showed much stronger associations with continuation or discontinuation. The findings suggest that recruitment failure reflects organizational and infrastructural constraints rather than shortcomings in consent communication. Ethically robust communication remains essential, but efforts to improve accrual should target structural conditions that support feasible trial delivery.