Motivators and barriers to clinical trial participation: a comparative review across socio-cultural and healthcare contexts

Abstract

Clinical trials remain essential for the advancement of evidence-based medicine and the development of new therapies. However, participant recruitment and retention continue to pose significant challenges globally, with under-enrolment affecting the success and generalisability of many clinical studies. Understanding the factors that motivate or hinder participation is therefore critical for improving recruitment strategies and ensuring equitable representation in clinical research. This study employed a systematic literature review and thematic synthesis of peer-reviewed journal articles, institutional reports, and patient perception surveys published between 2016 and 2026. Databases searched included PubMed Central, ScienceDirect, Semantic Scholar, and selected industry reports. The review identified personal benefit, altruism, and contribution to medical advancement as the most recurrent motivations for participation in clinical trials. Personal benefit, particularly access to advanced healthcare, close medical monitoring, and financial incentives, emerged as the strongest motivator across most studies. Major barriers included fear and safety concerns, lack of awareness, logistical constraints, mistrust in healthcare systems, financial limitations, and infrastructural inadequacies. Clinical trial participation is shaped by a complex interaction of individual, cultural, institutional, and systemic factors. While motivations are relatively consistent globally, barriers are more context-specific, particularly in developing countries. Improving public education, strengthening trust in healthcare systems, decentralising trial access, and enhancing infrastructural and regulatory capacity may improve participation rates and diversity in clinical research.