Retain more patients: Learn how to boost engagement in long-term clinical trials

Retaining Patients Isn’t Just a Metric, It’s a Strategy

In today’s hyper-competitive clinical trial landscape, recruiting patients is no longer the toughest part, retaining them is. While recruitment is trending upward globally, patient retention is quietly slipping, and that’s becoming a costly and urgent problem.

This isn't just a side issue for executives, procurement leaders, and sponsors. It’s a strategic concern affecting data quality, trial timelines, and financial return.

Retention Numbers That Should Worry You

Contrary to popular belief, clinical trials don’t typically exceed their enrollment goals, in fact, they often fall short. According to the Tufts Center for the Study of Drug Development (CSDD), patient recruitment remains one of the biggest hurdles in clinical research.

Despite innovations like decentralized trials and digital recruitment strategies, a large share of studies still struggles to enroll participants on time. Recent findings underscore that while some progress has been made, meeting enrollment targets continues to be a critical challenge across most therapeutic areas.

Especially in later phases, patient dropout remains a persistent obstacle in clinical trials. Recent data show that overall dropout rates in late-stage trials have risen to 19.1%, up from 15.3% in 2012. The problem is particularly acute in high-burden therapeutic areas: oncology trials report dropout rates nearing 20%, while central nervous system trials exceed 25%, reflecting the logistical, emotional, and physical toll these studies place on participants.

In practical terms, that means nearly 1 in 5 to 1 in 4 patients will not complete their participation with serious consequences for trial integrity, costs, and time to market

This isn’t just a statistical hiccup, it leads to missing data, protocol deviations, extended timelines, and a higher cost per data point.

Why Investigators Matter

When it comes to improving clinical trial retention, one of the most undervalued yet transformative levers is site and investigator engagement. While sponsors often focus on protocol design, technology, or incentives, the investigator, the physician at the center of the trial site, remains the most immediate, personal link between study objectives and patient realities.

Investigators are not just protocol executors. They are relationship builders, translators of complex trial requirements, and navigators of patient concerns. Positioned at the intersection of science and human care, investigators witness firsthand the most common reasons patients disengage:

• Physical or emotional fatigue

• Confusion about study expectations

• Scheduling conflicts due to work or caregiving

• And transportation barriers that can make even a routine visit burdensome

These aren’t theoretical risks, they’re everyday realities. And no one understands those realities better than the local investigator.

When empowered with the right tools, flexible visit windows, patient education materials, transportation support, and the trust to personalize care within protocol boundaries, investigators can preempt dropout triggers before they escalate. For instance, they can explain the trial’s value in relatable terms, align visit schedules with a patient’s routine, or recognize when a participant is overwhelmed and needs reassurance rather than a reminder email.

Critically, investigators also understand patient context in ways that dashboards and metrics cannot. They know:

• Which patients lack access to childcare

• Who depends on public transport

• Who may struggle with literacy or digital tools

• Who show early signs of disengagement

Yet, too often, investigators are excluded from trial design decisions, burdened with administrative overload, or left unsupported in patient engagement efforts.

If we want to truly reduce attrition and improve the quality and representativeness of trial outcomes, we must invest in the people closest to the patient. That means treating investigators not as mere conduits for data, but as trusted partners, empowered, equipped, and respected for the pivotal role they play in bridging the clinical and human dimensions of research.

Supporting Sites with Practical Tools That Work

Improving trial retention begins by lightening the load on clinical sites. That means giving investigators access to intuitive digital tools that reduce manual data entry, simplify visit tracking, and seamlessly integrate with existing platforms like EHRs and CTMS systems. When site staff spend less time wrestling with technology, they can spend more time engaging with patients.

Practical support also includes clear, self-serve resources such as concise protocol summaries, FAQ sheets, and short video explainers, so investigators don’t have to pause for sponsor clarifications at every turn. Autonomy breeds confidence, especially in fast-moving or high-burden trials.

Critically, sponsors should treat sites as collaborators, not vendors. That means opening two-way feedback loops, acting on insights from the field, and making real-time adjustments when needed.

One example comes from a 2023 Tufts CSDD study, which found that trials that offered investigators mobile-based data capture tools and flexible communication channels saw a 12% higher participant retention rate than those that relied solely on centralized systems.

The bottom line? When sites are well-supported, trials run smoother, patients stay engaged, and data quality improves.

Rethinking Trial Design Around Real Life

To truly move the needle on retention, sponsors must go beyond logistics and embrace patient-centered trial design. That effort starts at the earliest stage, involving patients and clinical site teams in protocol development. When their lived experiences guide design decisions, it's easier to spot impractical visit schedules, overly burdensome procedures, or exclusion criteria that unintentionally block real-world participation.

A growing body of research supports this shift. Research by Getz et al. (2020) shows that protocols with lower participant burden, often achieved through more patient-informed design, are strongly associated with higher retention and completion rates in clinical trials. This reinforces the value of involving both patients and investigators early in the design process to avoid logistical and procedural barriers that can drive dropout.

Decentralization with a Human Touch

Decentralized clinical trials (DCTs), remote monitoring, and flexible visit schedules reduce participant burden without compromising data quality. But tech alone isn't enough.

A 2022 article in NPJ Digital Medicine emphasized that while DCTs offer convenience and flexibility, their success largely depends on pairing technology with robust site engagement and proactive communication strategies. The study found that digital tools alone are insufficient to maintain participant engagement or ensure protocol adherence across diverse populations.

Although ePROs, telehealth, and wearable devices have revolutionized how we collect data, but human support remains a retention driver. Whether it’s a study concierge, mobile phlebotomy, or a 24/7 helpline, trials perform best when patients feel seen and supported.

Hybrid & Adaptive Trials Built for Real-World Complexity

Increasingly, sponsors are turning to hybrid and adaptive trial designs that offer greater flexibility and resilience. These models allow for mid-trial modifications based on interim results, making trials more patient-responsive while maintaining scientific rigor.

A 2024 report published in the American Journal of Respiratory and Critical Care Medicine by the American Thoracic Society emphasizes that adaptive trial designs, those that allow for mid-trial modifications based on interim data, can significantly improve recruitment and retention in complex, long-duration trials for chronic diseases such as COPD and cardiovascular disease. The authors argue that these designs enhance feasibility and responsiveness, especially in real-world populations that are often underrepresented in rigid, static models.

The Business Case: Retention = Acceleration

According to Fortune Business Insights, the global clinical trials market was valued at $60.94 billion in 2024 and is projected to grow to $104.41 billion by 2032, reflecting a compound annual growth rate (CAGR) of 6.8%. By 2028, the market is expected to surpass $80 billion, driven by innovation in DCTs, patient-centric design, and increasing R&D across biopharma.

But as competition intensifies, speed and quality are everything. Trials that prioritize engagement and retention don’t just finish faster, they produce more reliable results and avoid costly delays caused by protocol amendments or participant attrition.

In fact, according to research from Tufts CSDD, protocol amendments and participant dropout in Phase III trials can each cost sponsors hundreds of thousands of dollars per incident. While not quantified per percentage point, these inefficiencies, often linked to poor design feasibility and high patient burden, can collectively lead to millions in additional trial costs.

What Pharma Leaders Should Prioritize

Pharma leaders must rethink their priorities if they want to accelerate impact. That starts with empowering investigators, the people patients trust most, and investing in sites with smart tools and flexible support.

Trials should feel like part of everyday life, not an extra burden. Most importantly, engagement shouldn't be treated as a checkbox at the end; it must be a core strategy from day one.

Because in today’s race to deliver breakthrough therapies, it’s not just about who recruits fastest, it’s about who retains best.

Explore how Rubix is helping life science leaders build smarter, patient-first trials with tools that empower sites, streamline workflows, and drive retention from the ground up.