MDR Article 80 is the legal basis for adverse event reporting during clinical investigations. The sponsor must record every adverse event identified in the clinical investigation plan as critical to the evaluation of the results, every serious adverse event, every device deficiency that could have led to a serious adverse event, and any new findings in relation to those events. Serious events and reportable device deficiencies must be reported without delay to every member state in which the investigation is being conducted, through the electronic system set up under Article 73. The operational rulebook is Annex XV and EN ISO 14155:2020+A11:2024. The timelines are short, the definitions are strict, and the sponsor role does not scale down for small companies.

By Tibor Zechmeister and Felix Lenhard. Last updated 10 April 2026.

TL;DR

  • MDR Article 80 governs the recording and reporting of adverse events and device deficiencies during clinical investigations conducted under Article 62(1).
  • The sponsor is the legal party responsible for the reporting. The investigator feeds the data up to the sponsor; the sponsor files the reports with the competent authorities.
  • Article 80(2) requires reporting "without delay" for serious adverse events with a causal relationship to the device, comparator, or investigation procedure, and for device deficiencies that could have led to a serious adverse event.
  • The classification of serious adverse events against EN ISO 14155:2020+A11:2024 is the standard operational anchor for what counts as serious and how severity, causality, and device relatedness are assessed.
  • Ethics committee notification runs in parallel under national procedure and is not optional.
  • The electronic system under Article 73 is the reporting channel. Until it is operational in full, national procedures apply in each member state where the investigation runs.
  • The most common mistakes are late reporting, weak causality assessment, and treating device deficiencies as a separate workflow from SAE reporting.

Why this matters before the first patient is enrolled

A clinical investigation under MDR is the single regulated environment in a startup's life where a bad day and a slow email can become a legal non-compliance within hours. The reporting obligations under MDR Article 80 are not housekeeping. They are the mechanism through which competent authorities keep clinical investigations safe in real time, and the mechanism through which a sponsor demonstrates that it is actually running the study rather than signing protocols and hoping.

Founders sometimes arrive at the clinical investigation with the rest of the regulatory file already built. They know Annex XV. They have read Article 62. They have written a clinical investigation plan and they have an ethics committee submission drafted. And then the question arrives, usually from a monitor or a sparring partner: who on your team is on the hook for Article 80 reporting, on which day, to which competent authority, through which channel, with which template, and how is the first SAE going to get logged within the first hour it is recognised? If the answer is not ready before the first subject is enrolled, the answer is not ready.

This post is the operational walkthrough of what Article 80 actually requires, how the sponsor has to build the workflow, and where startups most often get it wrong. It is a companion to our post on what a clinical investigation is under MDR, our post on sponsor obligations under MDR Articles 62 and 72, and our pillar on the Subtract to Ship framework for MDR compliance.

What counts as a serious adverse event in the clinical investigation context

MDR Article 2 contains the defined terms used throughout Chapter VI, and Article 80 relies on those definitions. In operational practice, a sponsor running a clinical investigation under Article 62(1) anchors the classification of events against EN ISO 14155:2020+A11:2024, which defines adverse events, serious adverse events, adverse device effects, serious adverse device effects, and device deficiencies in a way that is compatible with the Article 80 reporting categories.

The short version: an event is a serious adverse event when it leads to death, is a serious deterioration of the health of a subject, is a life-threatening illness or injury, results in permanent impairment of a body structure or function, requires in-patient hospitalisation or prolongation of existing hospitalisation, results in medical or surgical intervention to prevent one of the above, or is a chronic disease, or is a foetal distress, foetal death, congenital abnormality, or birth defect. This is the classification scheme EN ISO 14155:2020+A11:2024 operationalises, and it is the scheme the sponsor is expected to use when deciding whether to report.

A device deficiency is an inadequacy of the investigational device relating to its identity, quality, durability, reliability, safety, or performance. A device deficiency that could have led to a serious adverse event — had a suitable action not been taken, had intervention not occurred, or had circumstances been less fortunate — is itself reportable under Article 80(2). This is the category founders most often miss: not a harm that happened, but a near-miss that could have caused one.

Each event, once recorded, is classified for severity, for causality to the device or the investigational procedure, and for expectedness against the investigator's brochure. The combination of these three dimensions drives the reporting decision.

MDR Article 80 reporting timelines

Article 80(2) requires the sponsor to report "without delay" to every member state in which the clinical investigation is being conducted any serious adverse event that has a causal relationship with the investigational device, the comparator, or the investigation procedure, or where such causal relationship is reasonably possible, and any device deficiency that could have led to a serious adverse event if suitable action had not been taken, if intervention had not occurred, or if circumstances had been less fortunate.

Article 80(3) requires the sponsor to also report any new findings in relation to any event referred to in paragraph 2.

"Without delay" is a deliberately tight phrase. EN ISO 14155:2020+A11:2024 operationalises the timelines for sponsor-to-authority reporting in the ranges that good clinical practice recognises — immediately for anything that signals an imminent risk to other subjects, and within very short defined windows for all other reportable events and device deficiencies. The exact window applied in practice depends on the national procedure of the member state where the investigation runs and on the procedure the sponsor has set up in the clinical investigation plan to meet Article 80 and the harmonised standard together.

The operational rule to internalise: a reportable event under Article 80 is not something that can wait until Monday morning. The workflow has to support recognition, classification, sponsor review, and competent authority reporting on a timeline measured in days at most, and in some cases in hours.

The sponsor reporting flow

The reporting flow is a chain with five links, and all five have to be in place before enrolment begins.

Recognition at the site. The investigator or a delegated team member identifies the event during a visit, in a follow-up call, through a laboratory result, or through a hospitalisation notification. The clinical investigation plan and the investigator's brochure specify how the site is trained to recognise events that are in scope for reporting.

Site-to-sponsor notification. The investigator notifies the sponsor within the timeline set in the clinical investigation plan, which must be short enough for the sponsor to meet Article 80 in turn. EN ISO 14155:2020+A11:2024 is the standard for what "short enough" looks like in practice; the sponsor writes the specific timeline into the plan and trains every site against it.

Sponsor classification and causality assessment. The sponsor reviews the notification, classifies the event against the Article 80 reportability categories, assesses causality to the device or procedure, and decides whether the event is reportable. For device deficiencies, the assessment includes the "could have led to a serious adverse event" test.

Sponsor-to-competent-authority reporting. The sponsor submits the report through the electronic system set up under Article 73 once it is operational for this purpose. Until it is, national procedures apply in each member state where the investigation runs, and the sponsor has to know exactly what channel, form, and deadline each authority expects. Article 81 empowers the Commission to adopt implementing acts further specifying the procedures and formats, and the sponsor checks the current status of those acts before the investigation begins.

Follow-up reporting. New findings related to a previously reported event are reported under Article 80(3). This is not optional. The reporting relationship with the competent authority continues for the life of the event.

Each link in the chain is a potential point of failure. A missing step anywhere in the chain is a non-compliance, and the non-compliance lives in the sponsor's record.

Ethics committee notification

Article 80 is primarily about the sponsor-to-competent-authority flow, but the ethics committee that approved the investigation is a parallel stakeholder with its own expectations. National law and national ethics committee procedures determine exactly which events are reported to the committee and on which timeline, and the sponsor is responsible for meeting those expectations alongside the Article 80 reporting.

In practice, the sponsor builds a single internal workflow that routes every reportable event to both the competent authority and the ethics committee, with the timelines set by whichever of the two is tighter. This avoids the failure mode where the sponsor files a competent authority report on time but forgets the committee, or vice versa. The committee signs off the reporting plan as part of the original ethics approval — which means the plan is testable against the approval document from day one.

For the detail on the ethics committee pathway itself, see our post on ethical approval for clinical investigations under MDR.

Eudamed and the Article 73 electronic system

MDR Article 73 provides for an electronic system on clinical investigations as part of Eudamed, through which clinical investigation applications, sponsor reports on adverse events and device deficiencies, and the end-of-investigation reports move between sponsors, member states, and the Commission. The Article 73 system is the legal reporting channel for Article 80 reports once it is operational for that function in the member state concerned.

The practical reality a startup has to track is the current status of the Eudamed modules relevant to clinical investigations. Until a given module is fully operational, the member states run their own national procedures for receiving Article 80 reports, and the sponsor has to know which procedure applies in each country where the investigation runs. This is not a theoretical point — a sponsor filing a report through the wrong channel is a sponsor that has not filed the report. The clinical investigation plan records the channel per country, and the sponsor checks the status of Eudamed and of the national procedures before enrolment starts and at every protocol amendment.

Common mistakes in Article 80 reporting

Seven failure modes show up again and again when we look at how startups set up and run adverse event reporting in clinical investigations.

Late reporting. The most common and the most damaging. An event is recognised at the site, sits in an inbox over a weekend, reaches the sponsor on Monday, and is reported three days later than it should have been. The record of the delay stays in the file.

Weak causality assessment. The sponsor marks the relationship to the device as "unrelated" without documenting the reasoning. A competent authority or a Notified Body later disagrees, and the reporting decision falls apart on review.

Treating device deficiencies as a separate workflow. Device deficiencies that could have led to a serious adverse event are reportable under Article 80(2). Sponsors sometimes file SAE reports diligently and treat device deficiencies as an internal complaint workflow instead, missing the reporting trigger.

Forgetting the "new findings" obligation. A reported event is closed in the sponsor's mind as soon as the initial report is filed. Article 80(3) requires new findings in relation to the event to be reported as they emerge, and this obligation continues for the life of the event.

Missing multi-state reporting. An investigation runs in three member states and the sponsor reports the event to the authority of one of them, assuming that the others will be informed through the system. Article 80(2) is explicit: reporting is to every member state in which the investigation is being conducted.

No pre-defined channel per country. The sponsor discovers on the day of the first reportable event that the national procedure for one of the countries is unclear, and the sponsor loses hours figuring out the channel when the clock is running.

Training sites on the plan but not on the reporting timelines. Investigators know what to look for but do not know how quickly they have to notify the sponsor. The site-to-sponsor link in the chain is the one that breaks quietest.

The Subtract to Ship angle

Adverse event reporting is the part of a clinical investigation where Subtract to Ship does the opposite of what founders expect. Subtraction elsewhere in the regulatory file means removing work that does not trace to a specific obligation. Subtraction in Article 80 reporting means removing ambiguity, not removing work. Every obligation in Article 80 and in the harmonised standard survives the test, because each one traces to a specific line in Regulation (EU) 2017/745 or in EN ISO 14155:2020+A11:2024.

What subtraction does here is strip the workflow to a single, unambiguous path. One recognition trigger at the site. One notification channel from site to sponsor. One classification checklist. One set of timelines, written into the plan, trained into the team, and testable against the next audit. One reporting channel per country. One archive for every filed report and every new finding. The Evidence Pass and the Operations Pass of the Subtract to Ship framework — see the Subtract to Ship framework pillar post — are what tell a founder whether the workflow they have drafted is the minimum that will survive an audit or a bloated version that will collapse under real event traffic.

The test is the same as every other part of the framework. Walk through every step of the reporting workflow and name the specific article, paragraph, or clause of the standard it traces to. If the answer is a clear citation, keep it. If the answer is "standard practice," rewrite it until it is traceable.

Reality Check — Where do you stand?

  1. Can you name, without looking it up, which specific MDR article governs adverse event reporting during clinical investigations and what it requires to be reported?
  2. Is the classification of serious adverse events in your clinical investigation plan anchored against EN ISO 14155:2020+A11:2024, and can you show how the two map?
  3. Who on your team is the named responsible person for Article 80 reporting, and what is their back-up?
  4. Do you know the reporting channel per member state where the investigation will run, and have you verified the current status of Eudamed and the national procedures?
  5. Have your investigators been trained specifically on the site-to-sponsor notification timeline, and is there a written record of that training?
  6. Does your workflow handle device deficiencies that could have led to a serious adverse event in the same lane as serious adverse events, or are the two separated?
  7. Is there a documented process for reporting new findings under Article 80(3), and does it continue past the initial report?
  8. Can you simulate a reportable event end-to-end from recognition to filed report without discovering a missing step?

Frequently Asked Questions

What is the legal basis for adverse event reporting in MDR clinical investigations? MDR Article 80 is the legal basis. It requires the sponsor to record adverse events that the clinical investigation plan identifies as critical, every serious adverse event, every device deficiency that could have led to a serious adverse event, and any new findings in relation to those events. The sponsor reports serious events and reportable device deficiencies to every member state in which the investigation is being conducted. Article 81 empowers the Commission to adopt implementing acts further specifying the procedures.

Who is responsible for Article 80 reporting — the sponsor or the investigator? The sponsor. The investigator at the site recognises and documents events and notifies the sponsor within the timeline set in the clinical investigation plan, but the legal reporting obligation to competent authorities under Article 80 sits with the sponsor. Where the sponsor is a startup, the sponsor is typically the company itself, and a named responsible person inside the company owns the workflow.

What timelines apply to Article 80 reporting? Article 80(2) requires reporting "without delay." The operational timelines are anchored against EN ISO 14155:2020+A11:2024 and the national procedure of each member state where the investigation runs. In practice, reportable events are filed within days at most and in some cases within hours, and the exact window is written into the clinical investigation plan and trained into the team.

Are device deficiencies reportable even if no harm occurred? Yes, if the device deficiency could have led to a serious adverse event had suitable action not been taken, had intervention not occurred, or had circumstances been less fortunate. This is explicit in Article 80(2). Device deficiencies are not a separate internal workflow — the near-miss category is part of the Article 80 reporting scope.

How does the Eudamed electronic system fit into Article 80 reporting? MDR Article 73 provides for an electronic system on clinical investigations as part of Eudamed, through which sponsor reports move between sponsors, member states, and the Commission. The sponsor checks the current status of the relevant modules before enrolment starts and at every amendment, and uses the electronic system where it is operational for the reporting function and the national procedure of each member state where it is not.

What standard operationalises Article 80 for good clinical practice? EN ISO 14155:2020+A11:2024 — Clinical investigation of medical devices for human subjects — Good clinical practice. The standard is the operational anchor for recognising, classifying, and reporting adverse events and device deficiencies in a way that is compatible with MDR Article 80 and Annex XV.

Sources

  1. Regulation (EU) 2017/745 of the European Parliament and of the Council of 5 April 2017 on medical devices, Article 73 (electronic system on clinical investigations), Article 80 (recording and reporting of adverse events that occur during clinical investigations), Article 81 (implementing acts), Annex XV (clinical investigations). Official Journal L 117, 5.5.2017.
  2. EN ISO 14155:2020+A11:2024 — Clinical investigation of medical devices for human subjects — Good clinical practice.

This post sits in the Clinical Evaluation & Clinical Investigations cluster of the Subtract to Ship: MDR blog. Authored by Felix Lenhard and Tibor Zechmeister. If you are building the Article 80 reporting workflow for a first clinical investigation and want a second pair of eyes on the chain from site recognition to competent authority report before the first subject is enrolled, Zechmeister Strategic Solutions works with founders on exactly that setup.