Patient acceptance of regenerative medicine trial designs for spinal cord injury in a nationwide web-based survey in Japan

Abstract

Abstract Patient acceptance of regenerative medicine trial designs in spinal cord injury (SCI) remains poorly understood. We conducted a nationwide, anonymous, web-based survey of individuals with SCI in Japan to assess willingness to participate in hypothetical regenerative medicine trials involving prolonged inpatient rehabilitation. The survey sequentially presented a single-arm scenario followed by a randomized two-arm scenario, and reasons for declining or conditional participation were collected. Participants were also asked whether a very small functional improvement, corresponding to a 2-point increase in the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) motor score, would be considered meaningful. Overall, 74.5% of the respondents indicated willingness to participate in the single-arm scenario, whereas 56.6% indicated willingness in the randomized two-arm scenario, suggesting that randomized trial structures requiring prolonged hospitalization may be less acceptable, while less burdensome trial structures may have higher acceptance. Across both scenarios, female sex, older age, and proxy responses were consistently associated with lower willingness. More than 70% of respondents regarded the very small functional improvement as a meaningful benefit, warranting trial participation. Although these findings may not translate into actual trial participation, they provide patient-centered evidence to inform the future regenerative medicine trial design.