How to reduce screen failure at your site

What counts as a screen failure?

A screen failure is a patient who signs the informed consent form, enters the protocol's screening period, and is not enrolled or randomized. The screen failure rate is screen failures divided by patients who entered screening.

The line that matters is consent. FDA guidance says informed consent must be obtained before any clinical procedure performed solely to determine eligibility for research, in line with 21 CFR 50.20.^⁠[11] Everything before that line is pre-screening: chart review, registry queries and phone calls. A patient ruled out at pre-screening costs review time. A patient ruled out after consent also costs a visit, procedures, and a slot another patient could have used.

Chart pre-screening before consent needs a HIPAA pathway, typically a review preparatory to research under 45 CFR 164.512(i)(1)(ii) or an IRB or privacy board waiver of authorization. The IRB and HIPAA outreach guide covers which one fits.

What screen failure rate should you expect?

There is no single industry rate, and published figures use different denominators. The broadest cross-therapeutic benchmark comes from Tufts CSDD, which reports a randomization rate: patients enrolled divided by patients screened. In its 2022 benchmark of 187 industry protocols approved between 2013 and 2018, Phase II protocols randomized 69.4% of screened patients and Phase III protocols 70.7%, so roughly 3 in 10 screened patients were not enrolled.^⁠[1]

Why do patients fail screening?

Screen failure reasons fall into four broad groups, and each calls for a different check before consent.

Criteria mismatch

The patient did not meet a criterion. Sometimes the evidence was already in a note, report or result nobody read against the protocol. Sometimes the criterion can only be measured at screening, such as an endoscopic score. At one IBD center, ineligible disease activity was the leading cause, at 36.4% of screen failures.^⁠[5]

Lab, imaging and clinical changes

Labs, scans and performance status change between referral and the screening visit, and results age out of the protocol window. In the early-phase oncology series, imaging findings caused 29.2% of screen failures, lab results 23.8% and performance status deterioration 11.9%.^⁠[2] At another institution, which left biomarker and stage failures out of its analysis, the most common reasons among solid-tumor patients were rapid disease progression (16%), ECOG performance status of 2 or worse (12%) and abnormal liver function tests (12%).^⁠[6]

Washouts and concomitant medications

The patient takes an excluded drug, or stopped a prior therapy too recently. These failures are predictable from the medication list and the last treatment date. FDA finalized guidance on washout periods and concomitant medications in cancer trial eligibility in July 2026, and a companion guidance on laboratory values notes that eligibility criteria are sometimes more restrictive than necessary.^⁠[14],[13]

Patient withdrawal and logistics

The patient decides against the study, cannot keep the visit schedule, or cannot get a required procedure done in time. Withdrawal of consent caused 9.1% of screen failures at the IBD center above. In the early-phase oncology series, administrative reasons, which included consent withdrawal and sponsor enrollment halts, caused 10.9%.^⁠[5],[2] A plain pre-visit call can bring some of these out before the slot is used.

What reduces screen failure before the screening visit?

The goal is to move every checkable criterion to the pre-screening side of the consent line. Five practices help.

1. 1

   Pre-screen against the full chart

   Read notes, pathology, imaging reports and outside records, not only the problem list. Record the evidence and its date for each criterion. The early-phase oncology authors suggest referring patients with brain scan and lab results already in hand.^⁠[2] The coordinator chart review checklist gives a format.

2. 2

   Set lab and imaging re-check windows

   For each time-bound criterion, write down the protocol window and the date the qualifying result expires. If the last result will be stale by the visit, plan a re-check. Results from routine care, which would happen with or without the study, may be used for eligibility without consent first; tests done only for the study wait until after consent.^⁠[11]

3. 3

   Check washouts against dates

   Compare the current medication list and the last dose of each prior therapy with the protocol's exclusions. When a prior therapy has already ended, book the screening visit for after the washout period, not before it. If a patient would stop a medication only to become eligible, FDA treats that washout as part of the research, so consent comes first.^⁠[11]

4. 4

   Make a pre-visit call

   Confirm current medications, recent admissions and new diagnoses. Ask about biopsies, washouts, placebo, the visit schedule, transport and, where required, a study partner. The pre-screening call script covers the questions.

5. 5

   Clarify criteria with the sponsor in writing

   Send ambiguous criteria to the sponsor or medical monitor before the first patient, and keep the answers in a criteria interpretation log. Where a criterion looks stricter than current guidance, say so. FDA's final performance status guidance (July 2026) says patients with ECOG PS 2 should be included in cancer trials unless a scientific or clinical rationale based on established safety considerations justifies excluding them.^⁠[12]

Which fix matches which cause?

Use this table to map each screen failure reason code to a pre-screening check and an owner.

How should you measure screen failure?

Track screen failure per study, per month and per reason. A single site-wide rate hides the problem.

• Screen failure rate: screen failures divided by patients who signed consent, for each study.
• Reason codes: one primary reason per failure, from a fixed list that matches the table above.
• Avoidable or not: whether the chart held the answer at pre-screening. This share tells you how much a deeper pre-screen could save.
• Pre-screen pass rate: patients who pass pre-screening divided by patients reviewed. A high pass rate paired with a high screen failure rate points to a shallow pre-screen.
• Days from pre-screen to screening visit: long gaps raise the chance that labs, scans and performance status change.
• Staff time per enrolled patient: coordinator hours per enrolled patient, counting time spent on patients who failed. At one cancer center, eligibility screening cost $129.15 to $336.48 per enrolled patient, depending on study phase.^⁠[10]

Share the numbers with sponsors. Reporting is uneven: in a review of 50 genitourinary cancer trials, only 24 published their screen failure rates.^⁠[3] Failure reasons and avoidable failures by study give the sponsor evidence for criteria clarifications and for its next site selection decision.

How does Bond help reduce screen failure?

Bond Health works on the pre-screening side of the consent line. Identify reads structured and unstructured records, such as notes and reports, against each inclusion and exclusion criterion. It ranks candidates and shows the evidence behind each criterion decision, so a coordinator can check the lab, the date and the note before calling anyone. Bond reports above 90% matching accuracy for eligibility screening and more than 50% less chart review time.^⁠[15]

Engage handles outreach, pre-screening questions and scheduling by voice and text, with scripts configured per site and study and escalation to coordinators. Patients are told AI assistance is used and can reach a person at any time: the agent transfers the call live to a coordinator or books a human callback, whichever the site prefers.^⁠[15],[16]

The dashboard reports patients matched, contacted, pre-screened, consented and randomized, along with screen-failure signals.^⁠[15] Bond does not publish a screen failure reduction figure, so track your own rate per study, before and after any change, with the measures above.

What should I do this week?

• Pull the recent screen failures for your highest-volume study and give each one a primary reason code.
• Mark each failure avoidable or not: was the answer in the chart before consent?
• For every time-bound criterion in that protocol, write down the window and add the expiry date to your pre-screen notes.
• Send the sponsor a written list of criteria your team reads differently, and start an interpretation log.
• Add a pre-visit call to every screening booking, using the pre-screening call script.
• Check how your clinical trial agreement pays for screen failures, including any cap.