An adverse event is any undesirable medical occurrence, injury, or harmful effect experienced by a patient, user, or other person associated with the use of a medical device, whether or not it was caused by the device. In regulated MedTech, certain adverse events must be reported to authorities within defined timelines.
What is an adverse event?
An adverse event (AE) is the broad term for any untoward outcome linked to a device during clinical use or investigation. ISO 14155, the standard for clinical investigations, defines an AE this way and separates it from an adverse device effect (ADE), an event the device actually caused or contributed to. Not every adverse event is device-related, but every one has to be assessed.
Adverse events sit in the clinical and post-market phases of the lifecycle. A patient injury, an unexpected reaction, or a harmful malfunction each starts as a signal the quality and regulatory systems must capture, evaluate, and, where required, report.
Why adverse events matter in medical device development
Adverse events are how the field tells you whether a device is as safe as the design files promised. Treating them as paperwork is where companies get into trouble.
The stakes are concrete. An unreported death or serious injury is a direct regulatory violation that can trigger warning letters, import holds, and recalls. Authorities also watch for patterns: one event may look minor, but a cluster of the same failure points to a systemic problem the manufacturer was expected to catch. Adverse events also feed the ISO 14971 risk management file, where real-world harm can shift the benefit-risk balance and force design or labeling changes. Caught early, a signal is a cheap correction; left alone, it becomes a costly field action under audit.
How adverse event reporting works
The mechanics differ by market, but the logic is the same: capture, assess reportability, report, investigate, and follow up.
In the United States, the FDA Medical Device Reporting rule (21 CFR Part 803) governs the process. Manufacturers submit through the electronic MDR system, generally on Form 3500A, on these timelines:
- 30-day reports for events where a device may have caused or contributed to a death or serious injury, or for a malfunction likely to cause harm if it recurs.
- 5-day reports when an event requires remedial action to prevent an unreasonable risk of substantial harm to public health, or when the FDA requests one.
In the European Union, the Medical Device Regulation (EU MDR 2017/745) uses the terms “incident” and “serious incident” rather than adverse event. Manufacturers file a Manufacturer Incident Report through EUDAMED under Article 87, on timelines set by severity:
- Serious public health threat: immediately, and no later than 2 days after awareness.
- Death or unanticipated serious deterioration in health: no later than 10 days.
- Other serious incidents: no later than 15 days.
Across both systems, the same upstream discipline applies. A complaint enters the quality system under ISO 13485 and 21 CFR Part 820, gets a reportability decision documented by a qualified person, and links to investigation and CAPA. Non-serious events are tracked for trends and reported when they cross a threshold, which the EU MDR covers under Article 88.
Common challenges and best practices
The most common failure is the reportability decision itself. Teams either over-report out of caution or talk themselves out of a report that should have gone in. Both look bad in an audit. A written decision procedure with a clear rationale for every call is what good looks like.
Timeliness is the second trap. The reporting clock starts on the awareness date, not after the investigation finishes, so slow complaint intake quietly eats the deadline. Build an intake that timestamps awareness and routes events the same day.
Separation of duties matters too. The person entering data should not be the only one approving a high-risk submission. Role-based review reduces errors and reads as control. Keep the system connected to trending: the same hazard appearing across lots or software versions is a signal to act on before an authority does.
How SJML helps with adverse event management
Syrma Johari MedTech (SJML) supports adverse event handling as part of its compliance services. Its QARA teams cover complaint intake and vigilance, including reportability assessment, adverse-event reporting, and the root cause analysis and CAPA that follow. SJML also supports post-market surveillance planning, periodic safety reporting, and field safety corrective actions, aligned to FDA and EU MDR frameworks and to ISO 13485 and ISO 14971 quality and risk systems. This helps teams meet reporting timelines and keep risk files current as real-world data arrives.
Frequently asked questions
An adverse event is any undesirable medical occurrence associated with a device. A serious adverse event is one that led to, or could have led to, a more severe outcome: death, a serious deterioration in health, or a threat to public health. Seriousness, not the device’s role, drives whether strict reporting timelines apply.
No. Only events that meet defined criteria are reportable. In the US, manufacturers report deaths, serious injuries, and certain malfunctions under 21 CFR Part 803. In the EU, only serious incidents are reported under EU MDR Article 87. Non-serious events are still documented, investigated, and watched for trends.
An adverse event is any harmful occurrence during device use, whether or not the device caused it. An adverse device effect is the subset where the device, its use, or a deficiency in it caused or contributed to the outcome. ISO 14155 defines both terms for clinical investigations.
It depends on jurisdiction and severity. FDA manufacturer reports are generally due within 30 days, or 5 days when urgent remedial action is needed. Under EU MDR, serious incidents are due within 15 days, deaths within 10 days, and serious public health threats within 2 days of awareness.
Related terms
- Post-Market Surveillance
- Medical Device Reporting (MDR)
- Field Safety Corrective Action
- Vigilance
- CAPA
