Pilot studies in clinical study design

Pilot studies in clinical study design

Guest post by Safeer Khan, Lecturer at Department of Pharmaceutical Sciences, Government College University, Lahore, Pakistan*

Introduction

Pilot studies are a cornerstone of modern clinical research. These preliminary trials allow researchers to assess the feasibility of their hypotheses, refine methodologies, and identify potential obstacles before embarking on larger, more expensive trials with significant ethical implications. A well-structured pilot study not only saves time and resources but also reduces the chances of costly failures during later phases of the clinical trial process. In contrast, poorly planned pilot studies often lead to what is known as “research waste.” This issue was highlighted in a review of 640 Phase 3 trials involving novel therapeutics, which found that 54% of them failed during clinical development [1].

This blog will delve into the four key elements that contribute to the success of a pilot study: study design, cost modelling, risk management, and the value of informativeness.

Enhancing Clinical Trials with Pilot Studies

Pilot Study Design

A poorly designed pilot study can lead to misleading conclusions. Underpowered pilots may falsely suggest that an intervention is ineffective, resulting in its abandonment. Conversely, overly optimistic results can advance weak interventions into larger trials, where they may ultimately fail. Similarly, a good pilot study design reassures regulators, funders, and ethics boards that further investment is justified.

While large trials aim for statistically significant results, pilot studies focus on fundamental questions such as whether recruitment targets can be met, if interventions are deliverable, and whether participants adhere to the study protocols. Similarly, in terms of sample size, pilot studies are not intended to detect treatment effects. Instead, they are selected to test feasibility endpoints. Julious (2005) suggested a “rule of 12,” meaning at least 12 participants per group to estimate parameters such as variance and recruitment rates [2]. While seemingly modest, such numbers can provide enough signal to forecast challenges in scaling up to hundreds or thousands of participants.

A well-designed pilot study design plays a crucial role in feasibility testing. Recruitment is often one of the first obstacles faced in trials. A survey by the Institute of Cancer Research, which involved 500 cancer patients, revealed that while 95% of patients were interested in participating in a clinical trial, only 11% actually enrolled. By simulating recruitment pathways, pilot studies help identify potential issues and reduce the risk of stalled enrollment, which is a major cause of premature trial termination. Beyond recruitment, pilots fine-tune protocols: randomization procedures, electronic data capture systems, and follow-up schedules. Such refinements protect full trials from costly operational missteps.

Check your trial design

Check your protocol

Upload your clinical trial protocol in PDF form to the Clinical Trial Risk Tool and check the design against our checklist. You can also create a per subject budget from the schedule of events.

Pilot Study Cost Modelling

Clinical trials are known for their high costs. National Institutes of Health (NIH) spends an average of $33.8 million on developing each drug, with $13.9 million allocated to Phase 1, $22.2 million to Phase 2, and $12.9 million to Phase 3 trials [3]. Read more: Clinical Study Cost Breakdown. Moreover, poor financial management is a major contributor to trial failure. A study found that 22% of Phase 3 trials were discontinued due to budgetary issues [1].

Pilot study cost modelling helps prevent such failures by acting as a “financial stress test.” For example, if a pilot involving 50 participants costs $250,000, investigators can estimate whether enrolling 5,000 participants in Phase III would be financially feasible. Additionally, procedures that are resource-intensive, such as MRI imaging, may seem manageable in a 20-patient pilot but could become unfeasible at a larger scale. Identifying such issues early on can help avoid significant financial misallocations.

Pilot studies also provide valuable financial insights by estimating recruitment costs, intervention delivery expenses, and monitoring needs. As funding bodies increasingly require clear evidence of feasibility and cost awareness before approving large grants, a pilot study that includes data-driven cost models strengthens the credibility of funding proposals. Due to this reason, the NIHR Guidance on Pilot Studies strongly recommends incorporating cost analysis in feasibility studies to ensure better budgeting accuracy.

Risk Management

When transparently reported, pilot study risks serve as “early warning systems” that strengthen the resilience of full trials. By converting risk into foresight, pilots transform potential liabilities into protective mechanisms. In particular, a pilot study can be employed to proactively address the following risks:

Ethical Risks

Every clinical trial carries inherent risks, but pilot study risk highlights them in a condensed form. The most serious ethical concern arises when pilots expose participants to interventions without generating valuable knowledge. Similarly, research lacking social or scientific value is inherently unethical, regardless of sample size. Therefore, ensuring a well-designed and purposeful pilot study is not only critical for the trial’s success but also for maintaining the ethical integrity of the research process.

Scientific Risks

Pilot studies are crucial in uncovering scientific risks, particularly the risk of misinterpretation. Since pilot studies are typically underpowered, they may produce false signals, either suggesting that an intervention is effective when it is not or discouraging further exploration of potentially promising treatments. Identifying these issues early helps prevent misdirection in research, ensuring that valuable interventions are not prematurely abandoned.

Operational Risks

Pilot studies provide a valuable opportunity to uncover operational risks early on. These failures often surface first in pilot trials, such as low recruitment rates, poor adherence, or logistical bottlenecks. Identifying these issues in a pilot study allows researchers to address them before they jeopardize larger trials.

Financial Risks

Pilot studies reveal financial risks by identifying cost-intensive elements that cannot scale. Without this early insight, full-scale trials are at risk of budget overruns, necessary amendments, or even collapse. Pilots help pinpoint inefficiencies in resource allocation, staffing, and infrastructure, allowing for adjustments before committing to large-scale expenditures.

Pilot Study Informativeness

A common criticism of pilot studies is their limited pilot study informativeness. Uninformative pilots waste resources and expose participants without contributing meaningful insights. Chalmers & Glasziou (2009) estimated that up to 85% of research investment is wasted [4], partly due to poorly designed and poorly reported pilots.

Pilot Study Informativeness describes how well the study contributes to understanding critical aspects of the research, such as feasibility, potential risks, and the effectiveness of interventions. For example, a surgical pilot study design that enrolls only eight patients without clear feasibility endpoints might add little value and could be criticized as unethical. On the other hand, an informative pilot in maternal health might demonstrate that sending text message reminders increases prenatal visit adherence by 35%, leading to a scalable intervention in Phase III.

Characteristics of Informative Pilots

  • Clear Objectives: Informative pilot studies are focused on specific feasibility questions, such as, “Can 20% of eligible patients be recruited within six months?”
  • Transparent Reporting: Publishing the results of a pilot study, even if they are negative, is crucial for preventing duplication of efforts and reducing research waste.
  • External Validity: A good pilot should reflect the diversity of populations and settings anticipated in the full trial. For example, if a new hypertension drug is tested only in urban hospitals, the feasibility findings may not be applicable to rural clinics, limiting the external validity of the study.

Conclusion

Pilot studies play a pivotal role in the clinical trial process, laying the groundwork for successful large-scale research. By addressing key aspects such as design, cost efficiency, risk management, and the ability to generate useful data, pilot studies reduce uncertainties and ensure the ethical integrity of clinical trials. As the demand for evidence-based treatments continues to grow, the value of well-conducted pilot studies cannot be overstated. They provide the critical insights needed to refine methodologies, minimize risks, and maximize the potential for successful outcomes, ultimately advancing the field of medical research.

References

  1. Hwang, T.J., et al., Failure of investigational drugs in late-stage clinical development and publication of trial results. JAMA internal medicine, 2016. 176(12): p. 1826-1833.

  2. Julious, S.A., Sample size of 12 per group rule of thumb for a pilot study. Pharmaceutical Statistics: The Journal of Applied Statistics in the Pharmaceutical Industry, 2005. 4(4): p. 287-291.

  3. Zhou, E.W., M.J. Jackson, and F.D. Ledley. Spending on phased clinical development of approved drugs by the US National Institutes of Health compared with industry. in JAMA Health Forum. 2023. American Medical Association.

  4. Chalmers, I. and P. Glasziou, Avoidable waste in the production and reporting of research evidence. The Lancet, 2009. 374(9683): p. 86-89.

5 Important Clinical Trial Financial Management Software Products to Use

5 Important Clinical Trial Financial Management Software Products to Use

Guest post by Youssef Soliman, medical student at Assiut University and biostatistician In today’s complex research environment, managing the finances of a clinical trial is as crucial as managing the science. Dedicated clinical trial financial management software solutions have emerged to oversee the monetary aspects of studies, helping maintain tight budgetary control and regulatory compliance. These platforms typically encompass capabilities like budget creation, real-time expense tracking, automated payments to sites and vendors, and the generation of audit-ready financial reports.

How can we create a clinical trial budget from the synopsis?

How can we create a clinical trial budget from the synopsis?

A number of documents are needed to produce a complete and accurate clinical trial budget. The necessary documents typically include: the study protocol (generally the most important document for building a budget) the informed consent form the clinical trial agreement or sponsor contract any laboratory and pharmacy manuals the charge master or schedule of fees the sponsor’s budget. However, sometimes a sponsor will send only the synopsis to a CRO when requesting a quote.

Building clinical trial budgets from the schedule of events: white paper

Building clinical trial budgets from the schedule of events: white paper

Are you wondering how you can build a detailed clinical trial budget from the protocol, whether for a site, CRO, or sponsor? This may appear an intimidating task. You have to read the protocol carefully, find the schedule of events, calculate how many times each activity occurs during the trial, and slowly create an itemised budget spreadsheet. There are cost items buried in footnotes that you need to look for.