How much do children with disabilities participate in Clinical Trials? A Scoping review

Children with disabilities (CWDs) are often excluded from scientific research, but no precise data are available on their participation in Clinical Trials. The aim of this study was to evaluate the rates of exclusion of CWDs from recent medical research.

The protocol of the study was designed according to Prisma-ScR guidelines. All completed interventional Clinical Trials registered on Clinicaltrials.gov between 2010 and 2020 related to the Leading 10 Level 3 causes of global Disability-adjusted life years (DALYs) for both sexes combined for all ages of the updated Global Burden of Disease Study 2019 were analysed. The exclusion criteria were considered explicit if related to the following categories: disability, physical impairment, cognitive impairment, behavioural or psychiatric disorders, language and communication impairment, sensory impairment. Any generic or poorly specified exclusion criteria or statements that left wide discretion to researchers were considered "implicit exclusion criteria". We assessed the appropriateness of explicit exclusion criteria in relation to the primary objectives of the trials and labelled them as "absolute", "relative", or "questionable".

The trials selected according to the inclusion criteria of the scoping review were 328; 166 (50.6%) were pediatric-only studies, and 162 (49.4%) trials comprising subjects of all ages. Explicit exclusion criteria were found in 82 trials (25%) and the disability category most frequently excluded was "Behavioural or psychiatric disorders" present in 46 trials (56.1%). Explicit exclusion criteria were considered "relative" in over 90% of the selected studies. Implicit exclusion criteria were present in 153 trials (46.6%) and the number and percentage of studies with at least one explicit or implicit exclusion criterion were 193 and 58.8% respectively.

This study highlights a high rate of exclusion of CWDs from medical research and the need for an inclusive approach that comprises the study design and any necessary adaptations for specific needs.