The Missing Patients in Clinical Trials

Health equity has become a key focus in healthcare and biomedical research. However, in clinical trials, equity is often only addressed during the recruitment phase, when clinicians discuss with patients whether to participate in studies that might provide a potential treatment or cure. These conversations are important but occur too late. 

By the time a patient is approached, many of the most critical decisions about who can realistically participate have already been made. The eligibility criteria, visit schedules, data requirements, and operational assumptions have quietly influenced the design of trials. At that point, health equity is no longer a matter of design; it becomes a negotiation.

Although most clinical trials succeed operationally, they may still fail to represent the populations most affected by disease. This results not only in health inequity but also potential missed scientific opportunities, leading to evidence that does not fully translate into real-world practice.

As a nurse working in clinical oncology and in biotechnology, the gap between trial design and real-world patients is hard to ignore. In clinical settings, clinical outcomes are rarely explained solely by patient behavior. When a discharge plan fails, clinicians don't assume patients lack motivation. Instead, we ask whether transportation was available, medications were affordable, health insurance exists, caregiving support was present, and whether instructions were realistic given the patient’s circumstances. Healthcare trains us to think this way - systems shape outcomes. The same reasoning applies when adherence issues occur. Clinicians are taught to look beyond intent. We consider the complexity, burden, access, and feasibility. When adherence fails, it often indicates a system that is misaligned with patients’ realities.

Clinical trials face the same reality. Clinical trial designs incorporate assumptions about time, flexibility, transportation, digital access, language, and social support. When these assumptions go unexamined, participation is feasible only for a limited group of patients, often those already overrepresented in research.

Designing trials around an idealized participant rather than real patient populations can produce evidence that is technically sound but clinically incomplete. These limitations become apparent later through uneven treatment responses, unexpected safety signals, and gaps between trial results and real-world outcomes. This represents a missed scientific opportunity. Patient representation is not just an equity issue; it is essential for reliable science.

Biotech and pharmaceutical companies influence participation conditions long before recruitment begins. Decisions on eligibility criteria, visit burden, operational complexity, and data collection requirements determine who can realistically enroll.

However, education about health equity often focuses on clinicians and study sites. They are asked to solve recruitment challenges after structural decisions are already made. This is not a matter of intent but of connecting trial design choices to their real-world impacts.

Evidence from insufficiently diverse patient populations weakens the generalizability of findings. Trials designed to promote broader participation generate data that more accurately reflect disease burden, treatment response, and safety across diverse populations. Therefore, health equity and data quality are not competing priorities. They are inseparable in rigorous scientific research.

Advocacy has long been a core value in healthcare communities. Clinicians are trained to anticipate harm, identify exclusion, and intervene when systems fail patients. These same principles should extend to the biotech and pharmaceutical industries, especially for those involved in designing, building, and conducting clinical trials, as a core competency or part of responsible research.

Clinical research aims to guide care for real people. Therefore, health equity cannot remain a downstream aspiration. It must be integrated into the design process: taught, expected, and measured among the teams that shape the eligibility criteria, operational burdens, and participation pathways. The biotech and pharmaceutical industries, whose trials generate evidence guiding treatment, must actively partner in advancing health equity.

The patients missing from clinical trials are rarely absent by chance. They are the product of decisions made long before recruitment begins.