The protocol was flawless. The patient still couldn't get there, or couldn't afford to, or couldn't complete the app-based tasks, or was never offered the study in a language they speak. None of that shows up in a feasibility model built around inclusion and exclusion criteria, and all of it decides who your trial is actually open to. It matters enough that the 2022 Food and Drug Omnibus Reform Act directed the FDA to require Diversity Action Plans to widen enrollment of underrepresented groups.
They can't get there
Transport friction is when a patient can't reliably reach the study site. It depends on distance, transit options, vehicle access, weather, and how often the protocol asks them to come in. The distances are real: a Journal of Clinical Oncology study of early-phase trial patients found a median travel distance of 36.4 miles, with more than half traveling 50 miles or more. Nationally, about 38% of adults over 35 would have to drive more than 50 miles to reach an NCI-funded research site. Missed visits rarely begin as non-compliance; they begin as a car that won't start or a route that got cut.
PRISM reads it across transportation access and distance-to-site, with rurality and healthcare density in support, using drive-time at real visit hours, transit coverage, and published dropout rates by distance band. The response is logistics, not luck: a transportation voucher program, a ride-share partnership, scheduled drivers, and in-home visits where the protocol permits.
They can't afford it
Cost friction is when a patient can't absorb the financial impact of participating: out-of-pocket expenses, time off work, lost wages, insurance gaps, and copays for routine care during the study. The burden is heavier than most protocols assume. In one study of early-phase oncology patients, 48% reported out-of-pocket costs of at least $1,000 a month, and about half said financial hardship made them less willing to take part in future trials. Most patients don't drop out over one big bill; they drop out because the small costs stack up until they exceed what the patient can carry, and it rarely gets logged as the real reason.
PRISM reads it across four models spanning insurance and coverage, out-of-pocket capacity, employment flexibility, and time off work for visits. The response takes the money question off the table: a reimbursement program sized to the patient rather than the budget, insurance navigation, up-front cost-coverage transparency, and support documenting paid time off.
Their basic needs aren't stable
Material hardship friction is chronic instability in the basics: food, housing, utilities. It's distinct from cost friction because it isn't a trial-specific expense; it's ongoing instability that predicts mid-study drop-off as life pressures compound. A patient behind on rent and rationing food will not make it to month six, however good the protocol is.
PRISM reads it across housing stability, food security, and utilities and material hardship, with neighborhood deprivation (the Area Deprivation Index and the CDC Social Vulnerability Index) as context. The response reaches past the trial: connect the patient to community resources for food, housing, and utility assistance, coordinate a case-management referral, and escalate when crisis indicators appear. Much of what gets scored as non-adherence is really survival.
They can't complete the digital parts
Digital access and skill friction is when a patient lacks broadband, a suitable device, or comfort with digital trial tools. It blocks remote visits, electronic surveys, app-based tasks, and video calls, and it hits electronic patient-reported outcomes hardest. The divide is measurable: Pew Research reports that 16% of US adults are smartphone-only internet users with no home broadband, and the FCC finds nearly 28% of rural residents lack access to high-speed broadband. Decentralized designs quietly assume a connection and a confident user, and the patients without either get filtered out.
PRISM reads it across broadband and device access and confidence with digital tools, using FCC county coverage maps alongside observed competence. The response closes both gaps: a device-lending program, broadband-subsidy navigation, tech-coach support, a paper backup for surveys when needed, and a simplified interface tier.
The study doesn't speak their language
Language friction is when a patient's preferred language isn't supported by the site or the trial materials. It's distinct from literacy: the question is which language, not how well the patient reads it. When staff and materials don't match the patient's language, the barrier sits with the trial, not the patient, and eligible people get excluded by default.
PRISM captures it through the language access model, comparing the patient's preferred language against site staffing and the language of the protocol and consent form. The response is straightforward and non-negotiable: materials and staff in the patient's language, certified medical-interpreter access at every visit, and consent-form language aligned to the patient.
These barriers are solvable once you can see them
What the social frictions have in common is that they're the most solvable barriers in the whole set, and the most invisible to a traditional feasibility process. A voucher, a device, an interpreter, a case-management referral: none require a protocol amendment, and all of them change who can take part. The only hard part is seeing the barrier early enough to act, which is the whole point of scoring readiness before enrollment rather than diagnosing attrition after it.
Sources and methodology.
This article synthesizes published research and public benchmarks with Jumo Health's PRISM readiness framework. Statistics are presented with their publication context; trial conditions and patient populations vary.
- Tufts Center for the Study of Drug Development, site enrollment performance benchmarks. View source
- CISCRP, 2023 Perceptions and Insights Study. View source
- Communications Medicine (Nature), 2025, trial representativeness of FDA-approved drugs. View source
- National Assessment of Adult Literacy (NAAL), US Dept. of Education / NCES. View source
- Paasche-Orlow et al., New England Journal of Medicine, 2003, consent form readability. View source
- Johns Hopkins Medicine IRB, informed consent readability guidance. View source
- Journal of Clinical Oncology (ASCO), 2022, travel distance in early-phase trials. View source
- Geographic access to NCI-funded cancer research sites (PMC). View source
- Patient-reported out-of-pocket costs in early-phase oncology trials (PMC). View source
- Pew Research Center, Internet/Broadband Fact Sheet. View source
- FCC, Broadband Progress Report (100/20 Mbps standard). View source
- Kogan et al., Psycho-Oncology, 2022, caregiver role in phase 1 trial decisions. View source
- Cerutti et al., Cancer Medicine, 2025, family system and trial retention. View source
- Tufts Center for the Study of Drug Development, protocol amendment benchmarks. View source
- Trials (Springer), 2025, retention and missing primary-outcome data review. View source
- US FDA, Diversity Action Plans (FDORA 2022). View source
