The development of new medicinal drugs is a long and complex process, taking up to 10 years on average to go from initial research to market approval. This highly regulated and planned cycle has many uncertainties, as biology and research can be unpredictable. In fact, only 12% of drugs entering clinical trials are eventually approved by the FDA. 
At any stage, a new medicine under investigation could fail to advance further.
The Importance of Recruitment and Retention
Amidst this risky drug development landscape, effective patient recruitment and retention are critical to the success of clinical trials. Having enough qualified, engaged participants is essential for obtaining statistically significant results and high-quality data. However, enrolling and retaining trial volunteers pose major challenges. It's estimated up to 90% of trials fail to meet original recruitment targets due to factors like strict eligibility criteria, trial location limitations, and protocol complexity. High dropout rates during the study also lead to insufficient participation and missing data, reducing statistical power.
Dedicated resources and strategies around recruitment planning, ethical incentives, minimizing patient burden, and ongoing communication can help ensure trials have the volunteer participation required. This enables collection of complete, timely data to determine true safety and efficacy. Robust enrollment and retention allow critical new treatments to advance steadily through trials to market approval, benefitting drug developers, patients waiting for new therapies, and overall public health. 
Recruitment and retention models are currently under global scrutiny, aimed at assessing how studies can be conducted more effectively.
This is particularly significant due to the potential obstacles that studies may face, whether stemming from participant-related issues or other factors. To ensure the seamless progression of clinical studies and to yield superior outcomes, researchers are compelled to furnish data that is both robust and ethically sound, all the while propelling medical advancement. Considering this, the meticulous selection and adept retention of participants emerge as pivotal factors.
Strategies for Successful Recruitment
Patient recruitment involves the use of strategies by sponsors, contract research organizations (CROs), study sites, or recruitment companies to identify and engage potentially eligible patients for clinical trials. These strategies are often built upon successful methods from previous studies. Efficiently selecting and recruiting patients within a reasonable timeframe is critical for the overall success of the study. The process of choosing patients is guided by specific criteria tailored to the study's objectives. 
One key objective in patient recruitment is inclusivity. The aim is to encompass a wide range of individuals from various backgrounds and characteristics. This inclusivity enhances the robustness and applicability of the study's findings, as it can account for diversity in responses and outcomes. In some cases, individuals may proactively volunteer to participate, enriching the data and providing valuable insights. 
In essence, the thoughtful selection and recruitment of human subjects streamline the research process and contribute significantly to the quality and comprehensiveness of the study's results. It allows for a more comprehensive understanding of the phenomena under investigation and ultimately advances scientific knowledge .
The Costs of Participant Dropout
The success of any study is intricately linked to the retention of patients, and this facet carries profound implications for various reasons.
When patients discontinue their participation, the study incurs not only a loss of valuable time and financial resources  but also the potential forfeiture of groundbreaking advancements in research (19% of clinical trials were closed or terminated due to failure to recruit enough participants ).
The ability to adeptly maintain patient engagement becomes a pivotal responsibility, primarily shouldered by clinical trials managers.
These managers serve as the linchpin in the patient retention process (the strategy and tactics designed to keep participants [who are] enrolled in clinical trials from discontinuing participation and dropping out. . Their multifaceted role extends to cultivating trust among participants, ensuring the legal, physical, and emotional well-being of patients (not sure), and, by extension, nurturing an environment conducive to the study's smooth progression and ultimate success. In essence, their role is to provide the essential support structure that keeps the study on course.
Nonetheless, retaining patients is not without its challenges. Obstacles, such as issues related to trust, budget constraints, and organizational inefficiencies, can jeopardize the study's integrity and progress. Effective management of these complexities is not only essential for the current study but also sets the stage for recruiting more willing volunteers for future research endeavors. .
Proposed solutions for recruitment and retention
Having a sound recruitment plan sounds the minimum requirement. However, this is critical for ensuring participant retention and trial completion is carefully planned, monitored and brainstorm upfront. Learning from previous trial shortcomings and assigning an experienced coordinator to lead recruitment will go a long way in boosting compliance. Both recruitment and retention plans must remain dynamic, as conditions dictated by the protocol and real-world patient populations can differ across sites and change over time. Factors like trial location, but also socioeconomic status, and geopolitics that may be omitted by study teams may influence the plan.
Key Considerations when creating a recruitment plan:
- Participant Characteristics: Consider demographics, personal attributes, education level, and compatibility with compliance requirements. Adult and pediatric trials demand different approaches.
- Motivations: Understand the patient's primary reason for participating, whether altruism, lack of treatment options, or a desire for free care.
- Barriers: Identify potential obstacles like lost work time, transportation, or mistrust of placebos.
- Incentives (as per local regulations): Discover motivators like small gifts, arranged transportation, or forms of appreciation.
Strategies to Optimize Recruitment and Retention:
1/ Protocol Design Phase:
- Engage all stakeholders, including patient groups if possible, as equal partners when designing the protocol.
- Gather site input on recruitment/retention challenges and reflect solutions in the protocol.
- Keep eligibility criteria and protocols simple yet pragmatic. Limit unnecessary study visits and/or assessments.
2/ Site Selection and Trial Phase:
- Choose sites based on feasibility data and access to the target population. Ensure qualified staffing, resources, and investigator experience.
- Conduct comprehensive site initiation visits to provide clarity on procedures.
- Provide adequate study budgets and prompt payment to motivate site staff.
- Set realistic enrollment milestones and routinely monitor performance.
3/ Communicating with Participants:
- Develop appropriate communication strategies and materials with IRB/EC approval.
- Advertise in newspapers, social media, medical offices to increase awareness.
- Create a database of potential volunteers. Partner with medical groups to promote the trial.
4/ Leveraging Decentralized Clinical Trial Tools
- Convenience - Enables remote participation from home rather than traveling to sites. This removes a major participation burden.
- Flexibility - Allows dosing, visits, etc. to be scheduled around the patient's lifestyle through in-home nurses, telehealth, mobile apps, etc.
- Broader Access - Patients who live far from research sites or lack mobility/transport can more easily take part. Widens recruitment pool.
- Continuity - Provides consistency with in-home healthcare workers vs. seeing different staff at sites. Can improve compliance.
- Comfort - Being in a familiar setting reduces stress and anxiety patients may feel at clinics, improving the experience.
- Empowerment - Patients feel more control over the process versus traveling to unfamiliar facilities. Fosters retention.
- Cost-Effectiveness - Reduces sponsor costs associated with brick-and-mortar sites and patient travel reimbursement.
- Data Quality - Direct-to-patient digital tools allow real-time data capture, improving accuracy over paper reports.
- Ongoing Contact - Telehealth and mobile apps enable more frequent check-ins between visits. Reduces dropouts.
- Scalability - Decentralized platforms facilitate large, potentially global trial populations not limited by sites.
5/ Additional Considerations:
- A nationwide database can identify "professional participants" who over-enroll.
- Incorporate study criteria into hospital management systems to filter ideal candidates.
- Provide clear explanations about the trial and diagnosis using plain, friendly language.
- Send reminders, thank you notes, small gifts to encourage retention. Recognize patient contributions.
- Leverage AI and machine learning to automate and optimize recruitment.
In summary, the ability to retain patients is a cornerstone of study success, equally vital as patient recruitment. It safeguards the study's credibility, secures invaluable data, and creates a positive ripple effect by potentially attracting more volunteers for subsequent studies, thereby advancing the frontiers of scientific knowledge.
The significance of patient recruitment and retention in clinical trials cannot be overstated. These twin pillars are indispensable elements that not only underpin the scientific validity of study outcomes but also ensure the safety and well-being of the participants who selflessly contribute to advancing medical knowledge.
Moreover, recruitment and retention strategies play a pivotal role in expediting the progress of medical research and translating scientific discoveries into practical applications within clinical settings. By addressing the diverse needs and concerns of participants, we bridge the gap between the controlled environment of a trial and the real-world scenarios where these treatments will ultimately be applied.
Recognizing that both recruitment and retention require ongoing attention and dedicated efforts, we not only safeguard the integrity of the research but also open doors to a deeper understanding of the diverse populations required for each study. This understanding, in turn, fuels progress in the realm of healthcare and medical science, offering hope for improved treatments, better patient care, and ultimately, a healthier and brighter future for all. Patient recruitment and retention are not mere administrative details; they are the lifeblood of medical progress.
 Innovation in the Biopharmaceutical Pipeline, PhRMA, 2021