How does study design influence the quality, risk, and costs of a clinical trial?

"Quality by Design" is a globally established approach aimed at ensuring the quality of clinical drug trials through the use of statistical, analytical, and risk-management methods during the conception, development, and manufacturing of medicinal products.

The most important course for a clinical trial is set before the first person is enrolled. Design flaws are difficult—or even impossible—to correct later on. The principle of building quality into the study concept from the start, rather than checking for it at the end, is known as "Quality by Design".

The term originates from pharmaceutical development (ICH Q8): all factors influencing a process are identified, understood, and controlled so that the result meets the specified characteristics from the outset. With the revised guideline for Good Clinical Practice for clinical trials, ICH E6(R3) (2025), this way of thinking has explicitly become the overarching principle for clinical trials. The goal is to protect the rights, safety, and well-being of participants while simultaneously generating reliable results.

For clinical investigations of medical devices, ISO 14155 does not use this specific term. However, its risk-based approach—graded according to the risk class of the device and the risk of the trial-related procedures—follows the same logic. It is therefore appropriate to apply Quality by Design to medical device studies as well.

What this means for study design

The focus is on the factors that are critical to the quality of a study: the data and processes without which neither participant safety nor the robustness of the results can be guaranteed (Critical-to-Quality factors). For these factors, the risks that threaten their integrity are determined, and measures are established that are appropriate to the risk—no more and no less. Study processes and risk mitigation strategies must be proportionate to the importance of the data being collected.

High-quality design also requires operational feasibility. Unnecessary complexity—too many endpoints, overly tight visit windows, data collection unrelated to the research question—increases sources of error, dropout rates, and costs without improving the validity of the findings.

Quality, risk, and costs are interconnected

A design that focuses on the essentials simultaneously reduces all three variables: fewer protocol deviations and missing data (quality), less burden and risk for participants (risk), and fewer corrections, amendments, and monitoring efforts (costs). Conversely, an overloaded or unclear design causes additional costs that remain invisible during the planning phase and only emerge during implementation.

A task for the entire project

"Quality by Design" begins in the conceptual phase—with the research question, endpoints, sample size, and processes—and is maintained throughout the entire study via quality management. Only through this holistic approach can it be ensured that a study is conducted ethically, achieves its objectives, and delivers results that manufacturers, authorities, and payers can rely on.

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MEDIACC brings Quality by Design into your project from the initial concept idea to the final study report—as an independent research institute and CRO for medical devices - Contact us for an initial consultation!