The clinical trial – direct data input for clinical evaluation

This blog post explains the role of clinical investigations as a primary source of evidence and direct data input for clinical evaluation (CER), the relevant regulatory requirements of the MDR, and how questions from CER, CEP, and PMS/PMCF are translated into a methodologically sound study design. We also demonstrate, in a practical way, how clinical investigations provide the crucial data to confirm safety and performance assumptions, substantiate claims, close data gaps, and seamlessly integrate results into CER, risk management, and the entire evidence loop.

Abbreviations

CEP	Clinical evaluation plan
CERIUM	Clinical Evaluation Report
CIP	Clinical Investigation Plan
MDR	Medical Device Regulation (EU Ordinance 2017/745)
Pmcf	Post-Market Clinical Follow-up
Pms	Post-Market Surveillance

Underlying regulations, standards and guidelines

EU Regulation 2017/745 (MDR)

ISO 14155

1 Introduction

Clinical investigations are the strongest and clearest source of evidence within the MDR – yet they are often treated as an isolated compliance component in technical documentation. They are, however, far more than that: clinical investigations provide the primary, prospective data that underpin clinical evaluation (CER), support claims, and answer key questions regarding a product's safety and clinical performance. This is precisely where their strategic importance lies as a direct interface to clinical evaluation.

Under the MDR, the expectation is clear: clinical evidence does not arise by chance, but follows a systematically planned, methodologically sound process. The clinical trial is the point at which hypotheses from the Clinical Evaluation Plan (CEP), data gaps from the Clinical Evaluation Framework (CER), and findings from the Product Management System (PMS) and Product Monitoring and Competence Framework (PMCF) converge. It is the place where crucial uncertainties are examined, endpoints are reliably quantified, and benefit-risk assumptions are objectively validated – before the product is launched and long afterward.

From a regulatory perspective, clinical trials are never isolated events, but rather embedded in the evidence loop required by the MDR: PMS identifies signals, PMCF confirms or refutes open questions, and clinical trials provide the robust, intervention-related data that are crucial for both marketing authorization and subsequent updates to the CER. This closed-loop system, as already described in the article on PMS as an interface to clinical evaluation, applies here in a more stringent form: No other data source provides comparable quality of evidence or methodological control.

This places clinical trials in a central position:

• They are the number one source of input for clinical evaluation.
• They define the basis of all clinical claims.
• They provide the prospective data that neither literature nor PMS/PMCF alone can replace.

And they ensure that statements about safety and performance are based on real clinical results, not assumptions.

In this article, we show how clinical trials function as an integral part of the CER, how questions can be systematically derived from CEP, CER and PMS/PMCF, and how manufacturers can set up clinical trials to deliver maximum regulatory, methodological and strategic value.

2. Key requirements for clinical trials

Under the MDR, clinical trials are no longer an optional tool, but rather form the backbone of robust clinical evidence. The regulatory requirements are clearly defined: While the MDR (Articles 62–82) establishes the legally binding requirements for planning, conduct, monitoring, and reporting, ISO 14155, as an international GCP standard, describes the scientific, ethical, and operational principles according to which every clinical trial must be conducted. Together, they form the binding framework for every study involving human subjects – from study design to data analysis.

At their core, both regimes require that clinical trials be scientifically valid, ethically sound, and methodologically sound. A clinical trial must never be a mere formality: it must generate prospective data that support the clinical evaluation, substantiate claims, and document the product's safety and performance under real-world conditions.

Basic principles that every clinical trial must meet

1. Ethics and patient protection

The protection of study participants is paramount. No trial may commence without informed consent, a proper risk analysis, continuous safety monitoring, and an independent ethics review. The MDR makes it unequivocally clear: patient safety is non-negotiable.

2. Scientific integrity

A clinical trial must follow a clearly defined study protocol – with precise endpoints, defined inclusion and exclusion criteria, and a statistically determined design from the outset. Only in this way can data be generated that are methodologically sound and regulatory valid.

3. Complete traceability

Each collected data record must be clearly attributable to the product version and configuration used. This traceability is crucial for subsequent clinical evaluation, especially when multiple generations or variants of a product exist.

4. Monitoring & GCP Compliance

ISO 14155 requires systematic monitoring to ensure that the study is conducted in accordance with the study protocol, regulatory requirements, and ethical standards. This includes site qualification, data validation, deviation management, and consistently documented GCP compliance.

5. Transparency and complete documentation

A clinical trial must be registered, all serious adverse events reported, and any deviations clearly documented. Completeness, traceability, and transparency are key criteria for notified bodies and authorities.

3. Endpoints as the linchpin – how clinical trials “feed” your CER

Clinical trials don't provide "just any" data, but ideally precisely the evidence you need for your clinical evaluation. The key to this is clearly defined endpoints. They translate the study objectives into measurable results – and thus directly into usable evidence for the CER.

3.1 Primary vs. secondary endpoints

Primary endpoints provide the central evidence for the safety or clinical performance of your product.

Typical examples include:

• Success rate of a procedure
• diagnostic accuracy (sensitivity, specificity)
• Rate of complications or adverse events

These endpoints are ultimately used to measure whether your core claims regarding safety and clinical performance are sustainable.

Secondary endpoints provide additional, in-depth information and help to round out the benefit profile, for example:

• Time until result or recovery
• User-friendliness and handling of the product
• Patient satisfaction or quality of life measures
• Workflow or resource effects in everyday clinical practice

The primary endpoint chosen is often key to convincingly demonstrating clinical benefits and benefit-risk assessments – especially in comparison to the state of the art.

3.2 Consistently link endpoints to the CER

For your clinical trial to truly function as data input for clinical evaluation, endpoints, CERs, and claims must be aligned from the outset:

1. Define your endpoints in the Clinical Investigation Plan (CIP) so that they directly reflect the claims that will later be included in the CER (safety, clinical performance, clinical benefit).
2. Link endpoints to the measurable parameters and benefit-risk criteria that you use in CEP and CER.
3. Choose objective, quantifiable and clinically relevant measures – subjective assessments without a clear scale are difficult for Notified Bodies to use.

3.3 Study design “backwards”: from CER to clinical trial

A well-planned study design not only meets GCP requirements but is also conceived from the outset as a source of evidence for the CER. The most pragmatic approach: Think of the study backwards.

Start with the preclinical assessment, which provides initial data for the clinical trial, or with the CER if one exists (in the case of PMCF studies), or:

Systematically analyze which gaps in the evidence exist:

• Where is the data weak or only indirect?
• Which claims are currently supported only by equivalence or literature?
• What open questions has the risk management identified?

Derive specific endpoints:

• Formulate primary and secondary endpoints in such a way as to close these gaps – e.g., through precise complication rates, performance indicators, or patient-relevant outcomes.
• Consider realistic usage conditions:
• Include representative users (e.g., different experience levels) and representative patient populations.
• Choose real-world settings so that the results can be credibly transferred to the CER and the assessment of the state of the art.

Plan the statistics according to the benefit-risk framework:

Specify in the CIP:

• which hypotheses are being tested,
• which effect sizes are considered clinically relevant,
• which confidence intervals or non-inferiority limits are needed to support your benefit-risk profile.

Pro tip:

"Backward design" – start with the questions you need to answer in the CER and plan the clinical trial precisely so that it addresses these questions with clear endpoints and robust statistics. Ultimately, it's not the quantity of data, but the quality and relevance of your endpoints that determines the true strength of your evidence in the CER.

4. How clinical trials directly support your claims – and why they are a key interface to risk management

Clinical trials provide not only data, but also the crucial, measurable parameters with which you can substantiate your clinical claims in the CER. This is precisely where their strategic importance lies: they generate those prospective, controlled, and reproducible results that no other data source can replace in this form.

4.1 Measurable parameters that substantiate claims

Every claim – whether relating to safety, clinical performance, or clinical benefit – must be substantiated with objective clinical data under the MDR. Clinical trials provide the most reliable basis for this, e.g.:

Performance claims

→ Accuracy, success rates, comparison to benchmark methods

Security claims

→ Complication rates, device-related adverse events, procedural success

Benefit claims

→ Patient outcomes, time to recovery, QoL scores

These parameters are not generated randomly – they are specifically collected via the defined primary and secondary endpoints. Therefore, the clinical trial is the direct source of input for the data you use in the CER to demonstrate that your product delivers on its promises.

4.2 Focus on security: The interface to risk management

Safety issues arising from clinical trials are not only relevant for the CER, but are also an essential component of risk management. The MDR requires a closed feedback loop between risk data and clinical evidence – and the clinical trial is the first and most important checkpoint in this loop.

The following safety-relevant information from clinical trials are key inputs for the risk management file:

Adverse Events (AE)

→ Frequency, severity, expected vs. unexpected events

Serious Adverse Events (SAE) and Serious Adverse Device Effects (SADE)

→ direct assessment of risk acceptance and residual risk

Complications and procedural errors

→ Identification of use errors, training needs, IFU adjustments

Device Deficiencies

→ potential product defects that may lead to corrective actions

This data is essential because it:

- validate the risk analysis,

- confirm or refute the assumption that "risks are acceptable",

- uncover new risks,

- and can trigger specific CAPA, IFU and design decisions.

4.3 The direct way back to CER and Risk File

The interlocking mechanism functions according to a clear sequence:

→ The clinical trial collects endpoint data that either confirm or relativize claims.

→ Security data is incorporated into the risk management file, including assessments of frequencies, severity levels, and probabilities of occurrence.

→ Performance and benefit parameters are incorporated into the CER, where they provide evidence of safety, performance, and clinical benefit.

→ If necessary, results lead to actions (IFU adjustment, design change, training, labeling, CAPA).

→ Changes are documented in the CER, Risk File and PMS system, creating the regulatory required evidence loop.

This makes clinical trials the main source of objective evidence – and at the same time the essential interface between CER and risk management.

5. Clinical trials in the evidence loop – how data flows cleanly back into CER, PMS, PMCF and risk management

Clinical trials are the starting point of the regulatory evidence loop. They generate the highest-quality data on the safety and clinical performance of a product – and this data must then be methodically and rigorously integrated into all related documentation and processes. The MDR requires a closed loop in which clinical evidence is continuously developed and updated.

5.1 From study data set to Clinical Evaluation Report (CER)

The clinical trial provides the primary data on which the CER is based – both for the initial approval and for subsequent updates:

Primary endpoints → direct confirmation of core claims (e.g., success rate, performance, accuracy)

Secondary endpoints → support clinical benefit and usability

Statistics and hypothesis testing → Basis for benefit-risk analysis

The results are systematically integrated into the CER at the following points:

• Evidence of safety and clinical performance
• Justification for risk acceptance
• Assessment of clinical benefit
• Comparison with the state of the art

Thus, the clinical trial forms the evidence-based core of the entire clinical evaluation.

5.2 Input for risk management – ​​validation, detection, adaptation

The safety-related results of the clinical trial are direct inputs for the risk management file (ISO 14971):

Validation of the existing risk assessment

→ Do the expected risks match the actual study results?

Identification of new risks or higher frequencies

→ Emergence of new AEs or variability in the application

Evaluation of use errors or design weaknesses

→ Basis for IFU updates, user training, or design changes

Quantification of residual risks

→ necessary for the final benefit-risk assessment

This makes clinical trials a crucial link between clinical evidence and risk management.

5.3 Relevant results for PMS & PMCF

For post-market processes, the clinical trial is more than just a starting point – it defines the basis against which all subsequent real-world data is measured:

PMS:

The event rates defined and measured in the study setup serve as comparison and reference values ​​to determine whether new signals are emerging in the market.

PMCF:

The clinical trial often defines the data gaps that need to be further investigated post-marketing:

• Long-term results
• rare complications
• Subgroup analyses
• Performance with extended user groups

PMCF thus builds directly on the results of the clinical trial and extends them into the post-market phase.

5.4 The regulatory process – the evidence loop in practice

The integration process is a closed one:

Clinical trials provide primary evidence:

→ Safety, performance, benefits, complication rates, usability

Data flows into CER, benefit-risk analysis, and state-of-the-art comparison. Security data is simultaneously integrated into risk management.

→ Verification, new risks, CAPA, IFU/label adjustments

PMS and PMCF strategies are defined based on the study data.

→ What open questions remain? Which hypotheses need to be tested after the market launch?

PMS/PMCF generate new real-world data that flows back into the CER and Risk File.

The CER is continuously updated:

→ as required by the MDR in Article 61

This creates a regulatory-required, audit-proof control loop in which the clinical trial is the first and strongest building block.

6. Conclusion

The clinical trial – if conducted – is the most evidence-based component of the clinical evaluation: methodically sound planning and GCP-compliant execution provide the primary, reliable data that substantiate claims, support benefit-risk analyses, and place the CER on an audit-proof foundation. It generates the measurable parameters with which manufacturers can demonstrate both safety and clinical performance and benefit – thus forming the backbone of any sound technical documentation.

At the same time, clinical investigations are a key interface with risk management: Adverse events, complications, and device-related incidents validate risk assessments, uncover new risks, and guide IFU, labeling, CAPA, and design measures. When properly integrated, clinical investigations link regulatory requirements with clinical reality and create the foundation for a complete evidence loop encompassing CER, PMS, and PMCF.

In short: A clinical trial is not a regulatory component in isolation, but a strategic instrument that increases patient safety, defines the quality of your clinical evidence and ensures long-term product compliance – provided it is properly planned, methodically documented and fully integrated with CER and risk management.

7. How we can help you

We support you throughout the entire clinical investigation lifecycle: from deriving precise research questions from CER, CEP, PMS, and PMCF, through study design, protocol development, sample size estimation, and setup, to data management, monitoring, biostatistics, and analysis. We prepare CIP and final reports and ensure that all results are seamlessly integrated into CER and PMCF reports and risk management – ​​for a consistent, robust, and audit-proof clinical evidence base.

Want to know more? Contact us for a free initial consultation!

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