Eyes on Research

Patient Centric Clinical Trials: Why Transportation Is a Timeline Risk

Written by 20/20 Onsite | Feb 23, 2026 2:33:39 PM

Patient Centric Clinical Trials: Reducing Transportation Risk to Protect Timelines and Data Integrity

Key Takeaways

  • Transportation barriers are not just patient experience issues, they are protocol execution risks that can lead to missed visit windows, deviations, and incomplete datasets.
  • Patient centric clinical trials that proactively reduce travel burden improve visit adherence and lower downstream operational strain on sites and CROs.
  • Travel mitigation strategies must balance accessibility with endpoint rigor, calibration controls, and clear oversight to maintain scientific integrity.
  • Sponsors who evaluate transportation risk early in protocol design are better positioned to protect timelines, retention rates, and overall study performance.

Patient centric clinical trials are often discussed in terms of empathy, convenience, and experience. Those matter. But for sponsors, the operational reason to care is more direct.

When patients miss visits because getting to the site is difficult, timelines slip, data gaps grow, and site burden increases. Transportation is not a soft issue. It is a protocol execution risk.

This article outlines what the data says about transportation barriers, how they affect enrollment and retention, and what sponsors can do to reduce risk while maintaining protocol integrity.

What the Data Shows About Enrollment, Retention, and Visit Burden

Clinical trials frequently struggle with enrollment and retention:

  • More than 80 to 90 percent of clinical trials experience delays, often due to enrollment challenges or patient dropout. Source: National Library of Medicine, systematic reviews on trial performance.
  • Approximately 30 percent of participants drop out of clinical trials before completion, with higher rates in longer and more complex Phase 3 studies. Source: NLM, PMC3684189.
  • Travel burden is consistently cited as a top barrier to participation in surveys of trial participants and investigators, particularly for patients with chronic disease or mobility limitations. Source: NLM, PMC10003583.

While exact percentages vary by therapeutic area and geography, the pattern is consistent. Distance, transportation logistics, missed work, caregiver coordination, and physical limitations contribute meaningfully to missed or rescheduled visits.

For sponsors, this translates into:

  • Missed visit windows
  • Protocol deviations
  • Increased variability in endpoint timing
  • Additional monitoring and rescheduling costs
  • Higher risk of incomplete datasets

Patient centric clinical trials are not simply about satisfaction. They are about reducing these downstream operational consequences.

Why Transportation Becomes a Protocol Risk

Transportation challenges compound in several predictable scenarios:

  1. Long study duration
  2. High visit frequency
  3. Elderly or mobility-limited populations
  4. Rural or geographically dispersed recruitment
  5. Specialized endpoints available only at limited sites

Each of these increases the probability that a participant will miss at least one scheduled visit. When that visit is tied to a primary or secondary endpoint, the impact is magnified.

Traditional mitigation strategies include:

  • Travel reimbursement
  • Ride-share partnerships
  • Adding additional investigative sites
  • Remote or hybrid visit models

These approaches can help, but each has trade-offs. Reimbursement does not eliminate logistical friction. Adding sites increases oversight complexity. Hybrid models require careful endpoint selection and validation.

The key question becomes: how can sponsors reduce travel burden without introducing additional operational variability?

Transportation and Data Integrity

Missed visits are not just schedule disruptions. They affect data quality in measurable ways:

  • Missed or out-of-window assessments reduce statistical power.
  • Repeated rescheduling increases inter-visit variability.
  • Delays in time-sensitive endpoints can alter interpretability.
  • Increased site workload contributes to monitoring findings and documentation risk.

Patient centric clinical trials that reduce visit burden often see improved adherence to visit schedules and reduced deviation rates. This does not replace site or PI oversight. It supports their ability to execute the protocol as designed.

From a sponsor perspective, the objective is clear: preserve protocol integrity while lowering avoidable friction.

Operational Models That Reduce Travel Burden

Several models are used today to reduce transportation risk:

1. Satellite or Community Sites

Expanding the site footprint closer to patients.
Trade-off: Increased oversight, contracting, and training complexity.

2. Decentralized and Hybrid Visits

Remote data capture and telehealth integration.
Trade-off: Not all endpoints are suitable for remote collection.

3. Point-of-Need Clinical Services

Bringing trained clinical teams and calibrated equipment closer to the patient, often in community-based settings.

This approach can reduce travel distance significantly. For example, in ophthalmic trials, community-based deployment models have demonstrated meaningful reductions in average patient travel miles when compared to centralized academic sites. Data from published sponsor case examples show reductions exceeding 80 percent in some programs.

The strategic benefit is not convenience alone. It is improved probability of visit completion within protocol windows.

Applying Patient Centric Design to Ocular Endpoints

Trials with ophthalmic endpoints present unique challenges:

  • Visual acuity testing
  • Optical coherence tomography
  • Intraocular pressure measurements
  • Fundus photography
  • Standardized refraction

These assessments require calibrated equipment, trained technicians, and protocol adherence. Historically, this limited them to specialized sites, often increasing travel burden for participants enrolled outside major metro areas.

When transportation becomes a barrier in ophthalmology-inclusive trials, sponsors face a specific risk:

Missed or delayed endpoint assessments that directly affect primary or key secondary outcomes.

In patient centric clinical trials that include ocular endpoints, sponsors should evaluate:

  • Geographic distribution of the enrolled population
  • Visit frequency tied to ophthalmic assessments
  • Feasibility of deploying standardized mobile or community-based ophthalmic services
  • Training, certification, and calibration controls
  • Data handling and CRO integration workflows

The goal is not to replace site oversight. It is to extend operational capability in a compliant, protocol-aligned manner.

A Sponsor Checklist: Is Transportation a Risk in Your Trial?

Consider these questions during protocol design and early enrollment:

  • Are patients traveling more than 50 miles for key visits?
  • Are visit windows narrow or tied to critical endpoint timing?
  • Is the population elderly, visually impaired, or mobility-limited?
  • Are missed visits already trending upward during early enrollment?
  • Are sites reporting scheduling strain or rescheduling frequency?

If the answer to several of these is yes, transportation is not a theoretical issue. It is an operational variable.

Designing Truly Patient Centric Clinical Trials

Patient centric clinical trials align participant experience with protocol performance. The most effective programs:

  • Reduce unnecessary travel without compromising endpoint rigor
  • Maintain calibration and standardized data collection
  • Integrate cleanly with sponsor and CRO oversight
  • Lower deviation rates tied to avoidable friction
  • Protect timelines by improving visit adherence

When done correctly, patient centric design strengthens both recruitment and retention while preserving data integrity.

Next Steps for Sponsors

If you are designing or managing a trial where travel burden may impact enrollment, retention, or endpoint timing, it is worth evaluating the operational model early.

A structured consultation can help assess:

  • Visit schedule risk
  • Endpoint sensitivity to missed windows
  • Geographic dispersion of the target population
  • Feasibility of alternative delivery models
  • Impact on monitoring and oversight

The objective is simple. Reduce avoidable friction. Protect the protocol. Improve the probability of on-time, on-budget completion.

If you would like to review transportation-related risk factors in your current or upcoming study, book a consultation to assess whether your trial design supports truly patient centric clinical trials without compromising scientific rigor.