Optimizing Screen Failures in Clinical Trials

Screen failures in clinical research are a necessary, unpredictable, and disruptive part of the process. How can something be all three of these things?   

They are necessary, in a sense, because the rigor of clinical research oftentimes demands a reasonably selective cohort of participants. While it certainly makes sense to cast as wide a net as possible to maximize enrollment, if the participant population is too heterogeneous, it makes it more difficult to understand if an investigational medication might work at all. Understanding the reasons for screen failure in clinical trials can help teams anticipate challenges and refine study design without compromising scientific rigor.

Summary

• Screen failures are inherent to maintaining trial rigor, yet are unpredictable and disruptive, driven by disqualifying medical histories and visit 1 protocol procedures.

• A substantial share—often about one-third—stem from medical history and are avoidable with clearer pre-screening and earlier access to records.

• When sponsors cap reimbursable screen failures (e.g., 3:1), sites can be disincentivized and slow or stop enrollment.

The Hard Truth About Screen Fail Ratios

Screen failure ratios – the number of participants that pass vs. fail the screening criteria – are also hard to estimate because humans and healthcare are complicated. Research scientists may do their best to estimate, say, a 3:1 screen failure ratio based on lots of great data, EMR analysis, and site feedback, yet still miss the mark by a mile. Though this unpredictability has been difficult to manage, we are at least able to categorize reasons for screen fails in the following two buckets:

• Medical history (prescribed intervention, comorbid diagnoses, etc.)

• Protocol screening procedures at visit 1 (labs, assessments, etc.). 

Teams often ask how to reduce screen failure rates in clinical trials; clearer pre-screening questions and better access to medical histories are practical starting points.

Avoidable Medical History-driven Failures

The sad truth is that many (if not all) of those patients who screen fail due to medical history, should never have walked in the door. In fact, according to Shea Overcash, Senior Director of Clinical Quality at Javara , “Approximately one-third of all screen failures are due to something found in the medical history, and in some studies, this is even higher.”

Anecdote: When Pre-Review Would Have Helped

Brad Hightower of Hightower Clinical Research once relayed a surprising story to us about a man who walked into his clinic for visit 1. This particular trial was enrolling patients that have undergone an amputation. Brad was curious to see a man with very life-like limbs and a normal gait walk through the door asking to be checked in for the visit. This man seemed to move so naturally, that Brad thought it must have been a high-tech prosthetic limb. Upon further conversation, it became clear that this man had all of his limbs intact, down to the pinky. 

This man took off half a day to be there, and the clinic staff blocked off the same amount of time to conduct this lengthy visit. But in the end, it was a total waste. How could this have happened?  Or more importantly, how could this have been prevented? The answer is obvious: were the staff able to review the medical records before scheduling the visit, the mishap would have been avoided. 

But Wait, It Gets Worse: Operational and Financial Impact

Scenarios like the above happen all the time and are extremely disruptive to all involved.

• The patient wastes their time and ends up feeling as if they did something wrong.

• The research site loses time and revenue that could have been spent to conduct a full visit, and the Sponsor further delays data collection.

Many sponsors pay for screen failures according to a predetermined ratio—e.g., 3:1. In other words, they will only pay the cost for 3 screen fails, for every 1 randomized. When participants screen fail for avoidable reasons and the sponsor doesn’t adjust their payment model, what do you think happens at the site? Yep, they just stop enrolling. 

💡What’s the sponsor and site perspective on screen failure ratio payments? Watch the recap of our Last Mile of Patient Recruitment webinar, featuring representatives from Gilead Sciences and Epic Medical Research, to find out 

How ProofPilot Helps

ProofPilot’s recruitment technology was designed with this in mind. Our intelligent pre-screeners leverage features like automatic theming, advanced branching logic, and geolocation, helping sponsors to efficiently screen potential participants and ensure they meet specific study needs. Schedule a call with us to learn more. 

Q&A

What are the main reasons participants screen fail?

Screen failures typically fall into two buckets: 1) medical history issues (e.g., disqualifying prior treatments or comorbidities), and 2) Visit 1 protocol procedures (e.g., lab results or assessments). A substantial share—often about one-third, and sometimes higher—stems from medical history issues that could be avoided with clearer pre-screening and earlier access to records.

What is a screen failure ratio, and why is it hard to estimate accurately?

The screen failure ratio is the expected relationship between failed and successful screenings (e.g., 3:1). It’s hard to predict even with EMR analyses and site input because individual patient factors and real-world processes are variable. When sponsors cap reimbursable screen failures at a ratio (like 3:1) and don’t adjust for avoidable failures, sites can become disincentivized and may slow or stop enrollment.

How can avoidable screen failures—especially those tied to medical history—be reduced?

Use clearer pre-screening questions and secure earlier access to medical records before scheduling visit 1. Simple record checks can prevent wasted visits, reduce participant frustration, and preserve site resources.

How does ProofPilot help address screen failures?

ProofPilot’s intelligent pre-screeners employ automatic theming, advanced branching logic, and geolocation to match candidates more precisely to study criteria. By improving pre-screening and aligning applicants to specific study needs, Sponsors can reduce avoidable failures, save time and cost, and keep studies on track.