Understanding participation of persons with disabilities in clinical trial research in India—a retrospective analysis of inclusive language of protocols

Abstract Background and objectives The under-representation of vulnerable groups in clinical trials, including persons with disabilities, could affect the applicability of trial findings to real-world public health interventions. We undertook this study to assess the extent to which persons with disabilities are excluded due to non-inclusionary language use in protocols from clinical trial research in India. Methods We conducted a retrospective mixed-methods analysis of fully published clinical trial protocols relevant to India (January 2017 to December 2024), sourced from national and international databases. Inclusion and exclusion criteria were analyzed with a focus on seven disability domains as defined by the Rights of Persons with Disabilities (RPWD) Act: locomotor disabilities, blood disorders, neurological disabilities, speech and language-related disabilities, hearing and vision-related disabilities, intellectual disabilities, and others. We executed a structured five-step coding process to assess patterns of disability-based exclusion in clinical trial protocols, determining whether exclusions were based on specific diagnoses or broad descriptions and whether justifications or supportive mechanisms were provided. To contextualize the findings, additional information regarding the trial phase, study location, and disease focus was extracted. An inductive analysis explored the language and rationale being employed for disability-related exclusions. Results Of the 11,975 records screened, 271 clinical trial protocols met the inclusion criteria. Among these, 117 (43.2%) protocols reported 126 instances of disability-related exclusionary language in the eligibility criteria. Exclusionary language pertaining to neurological disabilities accounted for the majority of exclusions (69.8%), followed by speech and language impairments (16.6%), blood disorders (9.5%), locomotor disabilities (3.1%), and hearing and vision-related disabilities (1%). Only 11.9% of these exclusions were explicitly justified based on diagnostic criteria, whereas 17.4% lacked any stated justification for disability-based exclusions. Exclusionary languages were notably higher in phase 3 trials (49.2%) and in international or multicentric trials (54.7%) compared to trials conducted in India (44.4%). Additionally, 5.9% of protocols specified a requirement for enhanced cognitive ability for informed consent, yet none included provisions for supportive decision-making mechanisms. Interpretation and conclusions Over one-third of clinical trial protocols had ambiguous eligibility criteria and exclusionary language which may potentially exclude persons with disabilities. This highlights the need for promoting the use of supportive, transparent, and non-exclusionary trial protocol language.