Section 2
Key Changes from MDD to MDR
Understanding the significant regulatory evolution from the Medical Devices Directive (93/42/EEC) to the Medical Device Regulation (EU) 2017/745.
Why the Change Was Necessary
The transition from the Medical Devices Directive (MDD 93/42/EEC) to the Medical Device Regulation (MDR 2017/745) represents the most significant regulatory change in the European medical device industry in over 25 years. This shift was driven by several critical factors that exposed weaknesses in the previous regulatory framework.
The MDD, implemented in 1993, served the industry well for many years. However, high-profile incidents such as the PIP breast implant scandal (2010) and the metal-on-metal hip implant failures revealed gaps in device oversight, clinical evidence requirements, and traceability systems. These incidents affected thousands of patients across Europe and highlighted the need for more robust regulatory controls.
Unlike the previous directive system where member states could interpret requirements differently, the MDR is a regulation that applies directly and uniformly across all EU member states, ensuring consistent standards throughout the European healthcare system.
Fundamental Legal Difference: Directive vs. Regulation
MDD (Directive)
- Required transposition into national law
- Member states could interpret requirements differently
- Created inconsistencies across the EU
- Less uniform enforcement
MDR (Regulation)
- Directly applicable in all member states
- No national transposition required
- Uniform application across EU
- Consistent enforcement standards
Expanded Scope of Regulation
The MDR significantly broadens the scope of devices covered compared to the MDD. Healthcare workers must be aware that many products not previously regulated as medical devices now fall under MDR requirements.
Products Now Included Under MDR
Aesthetic Devices
Non-corrective contact lenses, dermal fillers, liposuction equipment, intense pulsed light equipment
Devices with Non-Viable Tissues
Products incorporating or consisting of substances of human origin (excluding blood, tissues, cells covered by other directives)
Devices for Cleaning/Disinfection
Products specifically intended for disinfection of medical devices
Implantable Products
Products intended to be totally or partially introduced into the human body through surgical intervention
Classification Rule Changes
The MDR expands the classification system from 18 rules under MDD to 22 rules under MDR. Several new rules address emerging technologies and device categories that did not exist or were not adequately covered in 1993.
| Change Type | MDD | MDR | Impact |
|---|---|---|---|
| Number of Rules | 18 classification rules | 22 classification rules | More nuanced risk assessment |
| Software | Often Class I or unregulated | Rule 11: Can be Class IIa, IIb, or III | Most medical software now Class IIa minimum |
| Nanomaterials | No specific rules | Rule 19: Specific provisions | Higher classification for nano-containing devices |
| Active Implants | Separate directive (AIMDD) | Integrated into MDR | Single regulatory framework |
| Reprocessed Single-Use | Not addressed | Article 17: Explicit requirements | Healthcare institutions have new obligations |
Special Focus: Software as a Medical Device (SaMD)
One of the most significant changes under MDR is the treatment of standalone software. Under MDD, many clinical decision support systems and diagnostic software were either unregulated or classified as low-risk Class I devices.
Under MDR Rule 11, software intended to provide information used to make decisions with diagnosis or therapeutic purposes is now classified based on the potential impact of those decisions:
Software intended to provide information used for decisions that could cause death or irreversible deterioration of health
Software intended to provide information used for decisions that could cause serious deterioration of health or surgical intervention
All other diagnostic/therapeutic software not covered above
Enhanced Clinical Evidence Requirements
The MDR substantially strengthens requirements for clinical evidence throughout a device's lifecycle. This represents one of the most resource-intensive changes for manufacturers and has direct implications for healthcare procurement and device evaluation.
MDD Approach
- Clinical evaluation could rely heavily on literature
- Equivalence claims were broadly accepted
- Post-market clinical follow-up (PMCF) was minimal
- Limited requirements for legacy devices
- Clinical data often not required for Class I devices
MDR Requirements
- Clinical evidence required for ALL devices
- Strict equivalence demonstration requirements
- Mandatory PMCF for most device classes
- All devices need updated clinical evaluations
- Access to equivalent device technical documentation required
Equivalence Under MDR
Under MDR, claiming equivalence to a predicate device now requires demonstrating similarity across three domains:
Clinical Equivalence
Same clinical condition, purpose, site in body, population, and relevant safety/performance characteristics
Technical Equivalence
Similar design, conditions of use, specifications, properties, deployment methods, and principles of operation
Biological Equivalence
Same materials in contact with tissues/body fluids, or materials with established safety profiles
Critical Change: Manufacturers must now have a contract with the equivalent device manufacturer to access their technical documentation, or demonstrate the equivalent device is their own. This effectively eliminates most third-party equivalence claims.
Unique Device Identification (UDI) System
The MDR introduces mandatory Unique Device Identification across Europe. Under MDD, there was no harmonized identification system, making device tracking during recalls extremely challenging.
UDI Implementation Timeline
26 May 2021
UDI carriers required on labels and higher-level packaging
26 May 2023
UDI carriers required on labels and higher-level packaging
26 May 2025
UDI carriers required on labels and higher-level packaging
26 May 2027
UDI carriers directly marked on device (direct marking)
Implications for Healthcare Workers: Hospital inventory systems, procurement databases, and patient records should be updated to capture and store UDI information. This enables better traceability, more efficient recalls, and improved patient safety documentation.
Economic Operator Obligations
The MDR clearly defines and expands the obligations of all economic operators in the supply chain. Under MDD, responsibilities were less clearly defined, particularly for importers and distributors.
| Economic Operator | Key New Obligations Under MDR |
|---|---|
| Manufacturer |
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| Authorised Representative |
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| Importer |
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| Distributor |
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Notified Body Designation and Oversight
The MDR introduces significantly more stringent requirements for Notified Body designation and ongoing oversight. This has resulted in a substantial reduction in the number of Notified Bodies operating in Europe.
Under MDD
- Approximately 80 Notified Bodies operated
- Variable competence levels across NBs
- Limited unannounced audits
- Inconsistent conformity assessment rigor
- "Notified Body shopping" was possible
Under MDR
- As of 2024, approximately 40 NBs designated
- Rigorous competence requirements
- Mandatory unannounced audits
- Standardized conformity assessment procedures
- Joint assessments by designating authorities
Impact on Healthcare Facilities
The reduced number of Notified Bodies has created capacity constraints, leading to longer certification times. Healthcare facilities may experience delayed availability of new devices or difficulty sourcing certified devices from new suppliers. Procurement teams should factor these market dynamics into their supply planning.
Expanded Post-Market Surveillance Requirements
Post-market surveillance (PMS) requirements have been dramatically expanded under MDR. Manufacturers must now implement comprehensive, proactive systems to continuously gather and evaluate real-world device performance data.
New PMS Documentation Requirements
Post-Market Surveillance Plan
Required for all devices. Must detail methods for collecting and analysing data, indicators for PMS, methods and protocols for periodic safety update reports (PSUR) or PMS reports.
Post-Market Surveillance Report
For Class I devices: summary of PMS results and conclusions, updates when necessary.
Periodic Safety Update Report (PSUR)
For Class IIa, IIb, and III devices. Annual updates for Class III and implantables; every two years for Class IIa and IIb. Must include benefit-risk analysis and PMCF conclusions.
Post-Market Clinical Follow-up (PMCF)
Proactive collection of clinical data throughout device lifetime. PMCF plan and evaluation report required. Results feed into clinical evaluation updates.
EUDAMED: The European Database on Medical Devices
EUDAMED represents a major transparency initiative under MDR. While a database existed under MDD, it was not publicly accessible and contained limited information.
EUDAMED Modules
Actor Registration
All economic operators and healthcare facilities must register
UDI/Device Registration
Core data elements for all devices placed on market
Notified Body & Certificates
Information on designated NBs and certificates issued
Clinical Investigations
Applications and results of clinical studies
Vigilance & PMS
Serious incidents and field safety corrective actions
Market Surveillance
Information exchange between competent authorities
Note: EUDAMED implementation has been phased. Healthcare workers can access the public database to verify device registrations, check certificate validity, and review field safety notices.
Case Study: Reclassification Impact on Hospital Software Systems
Situation: A regional hospital group in Germany had been using a locally developed clinical decision support system (CDSS) for antibiotic prescribing guidance. Under MDD, this software was considered Class I and self-certified by the in-house IT department.
MDR Impact: Under MDR Rule 11, the software was reclassified as Class IIa because it provides recommendations that could lead to treatment decisions affecting patient health. This required:
- Engagement of a Notified Body for conformity assessment
- Implementation of a Quality Management System (ISO 13485)
- Clinical evaluation demonstrating safety and performance
- Post-market surveillance system establishment
- UDI assignment and EUDAMED registration
Resolution: The hospital group faced a decision: invest approximately €300,000 in compliance activities over 18 months, or discontinue the software. After analysis, they partnered with a commercial medical device software company that had already achieved MDR certification for a similar product, integrating their existing clinical protocols into the compliant platform.
Lesson for Healthcare Workers: In-house developed software solutions may now require substantial compliance investment. Early identification of such systems and assessment against MDR classification rules is essential for planning and budgeting.
Case Study: Supply Chain Disruption from Equivalence Changes
Situation: A community healthcare provider in Ireland relied on a specific wound care dressing from a mid-sized European manufacturer. The product had been CE marked under MDD based on equivalence to a well-established competitor's device.
MDR Impact: Under MDR's stricter equivalence requirements, the manufacturer could no longer claim equivalence without access to the competitor's technical documentation. Without sufficient standalone clinical data, the manufacturer announced discontinuation of the product line in the EU market.
Actions Taken:
- The procurement team identified the supply risk 12 months before the discontinuation date
- Clinical staff evaluated alternative MDR-compliant products through a structured product evaluation
- Training was conducted for wound care nurses on the new product characteristics
- Patient records were updated to reflect the product change where relevant
Lesson for Healthcare Workers: Monitor supplier communications regarding MDR transition. Products with historical equivalence-based certification may face discontinuation. Build product evaluation and switching protocols into procurement planning.
Summary: Key Differences at a Glance
| Aspect | MDD (93/42/EEC) | MDR (2017/745) |
|---|---|---|
| Legal Framework | Directive (national transposition) | Regulation (direct application) |
| Scope | Medical devices only | Medical devices + aesthetic products + AIMD |
| Classification Rules | 18 rules | 22 rules (including software, nano) |
| Clinical Evidence | Literature-based often sufficient | Clinical data required; strict equivalence |
| UDI | Not required | Mandatory for all devices |
| Traceability | Limited requirements | Full supply chain traceability |
| PMS | Minimal requirements | Comprehensive PMS, PMCF, PSUR |
| Database | Limited, not public | EUDAMED with public access |
| Importer Obligations | Minimal | Significant verification duties |
| Documentation Retention | 5 years | 10 years (15 for implantables) |
Key Takeaways for Healthcare Workers
Devices you currently use may face reclassification, discontinuation, or supply constraints during the MDR transition.
In-house developed software and devices now face significant regulatory requirements that may require commercial alternatives.
UDI implementation requires updates to inventory management, patient records, and procurement systems.
EUDAMED provides transparency on device certification status—use it for due diligence in procurement.
Manufacturers now have explicit obligations for post-market surveillance—healthcare facilities play a key role in reporting incidents.
Build MDR awareness into procurement specifications and supplier evaluation criteria.