NMPA usability guidance is the guideline of the Chinese regulatory authority National Medical Products Administration (NMPA), issued by its evaluation center CMDE, for assessing the usability engineering (human factors engineering) of medical devices. The guidance is intended to support manufacturers in building a usability engineering process and to standardize the requirements for technical review. The focus is on the safe and effective use of medical devices.
The final guidance was published on March 19, 2024; since October 8, 2024, the intended usability documentation has to be submitted with registration applications for medical devices of Chinese classes II and III. In vitro diagnostic reagents are excluded from the scope. The guidance is not an independent legal provision itself and allows justified alternative approaches.
- Risk-oriented approach of the NMPA
- High use risk devices as the central concept
- Decision logic for regulatory requirements
- Summative evaluation under Chinese conditions of use
- Relationship with the usability engineering process
- Typical challenges for international manufacturers
- Regulatory reference
- Frequently asked questions (FAQ)
Risk-oriented approach of the NMPA
The NMPA regards usability primarily as a component of product safety. At the center is therefore not general user-friendliness but the control of risks that can arise from use errors. The guidance classifies the use risk of a product into three levels (high, medium, low) according to the possible severity of harm and derives different requirements for evidence and documentation from this. The probability of occurrence is deliberately not used as the primary classification criterion because, according to the guidance, it is difficult to determine in the course of the review. The approach resembles the interplay of IEC 62366-1 and ISO 14971 but places a stronger focus on the regulatory assessment of the specific use risks.
High use risk devices as the central concept
An essential feature of the NMPA guidance is the distinction between products with low, medium and high use risk (low, medium and high use-risk). The classification is not based on the general product classification alone but on the potential consequences of use errors. Products with potentially serious consequences in case of misuse are subject to the most extensive human factors requirements. As a result, the depth of the required usability engineering process is directly coupled to the use risk. Decisive for current submission practice is the official High Use Risk Product Trial Catalogue: Class III products listed there, such as cardiac RF ablation catheters, robot-assisted surgical navigation systems or class III insulin pumps, submit a usability engineering research report; the remaining class II and class III products submit either the usability documentation required in product-specific guidance or, if no such requirements exist, a use error evaluation report.
Decision logic for regulatory requirements
The final requirements do not depend exclusively on the use risk. The guidance additionally takes into account the novelty of the product and the availability of suitable comparator products. This results in a decision tree that determines whether, for example, a simplified assessment based on existing data is sufficient or whether a comprehensive usability engineering investigation becomes necessary. This risk-adaptive approach in part goes beyond the requirements explicitly described in IEC 62366-1.
Summative evaluation under Chinese conditions of use
The guidance requires that differences in users and use scenarios between China and other countries be taken into account. For products with high use risk, these differences are to be analyzed; if they are not justifiable, the validation with Chinese users has to be repeated. Manufacturers must be able to justify why results from other markets are transferable or carry out additional investigations with Chinese users. This aspect resembles the FDA requirements regarding representative user groups but is oriented more strongly toward national applicability.
Relationship with the usability engineering process
The guidance does not start only at validation but looks at the complete development process. Comprehensible information is expected on intended use, user groups, use scenarios, critical tasks, identified use errors, risk control measures and results of formative and summative investigations. The use-related risk analysis forms the link between risk management and usability engineering.
Typical challenges for international manufacturers
A common misconception is that an FDA-compliant human factors file is automatically sufficient for China. The guidance has similarities with IEC 62366-1 in several areas; the annotated expert translation also points to parallels with FDA human factors requirements. The concrete documentation structure and the decision criteria differ, however. Particularly critical are missing justifications on the transferability of user data, cultural differences or use scenarios. Manufacturers should therefore check early on whether additional evidence is required for the Chinese market.
Regulatory reference
The “Guideline of Usability Engineering Review for Medical Devices” of CMDE/NMPA describes the regulatory expectations for usability engineering or human factors engineering in the Chinese approval procedure for medical devices; since October 2024, corresponding usability documentation has been required in the approval procedure for certain class II and III products. The NMPA is oriented in content to established human factors concepts and to FDA human factors guidance and is fundamentally compatible with the risk-based approach of IEC 62366-1 and ISO 14971 but contains product-specific regulatory decision logic. For high-risk products, comprehensive usability engineering evidence and validation activities can be required; in some cases an independently conducted test is expected.
An FDA-compliant human factors file is not automatically sufficient for China. The NMPA requires its own evidence on the transferability of user data and couples the depth of requirements directly to the classification as a low/moderate/high use risk device.
Frequently asked questions (FAQ)
Is the NMPA usability guidance identical to IEC 62366-1?
No. Although the guidance is clearly oriented to international usability engineering principles, it defines its own regulatory decision paths and documentation requirements for the Chinese approval procedure.
Is FDA human factors data sufficient for China?
Not necessarily. The NMPA can request additional evidence, in particular if cultural, linguistic or user-related differences could affect the transferability of the results.
Does the guidance affect all medical devices?
The guidance applies to registration applications for medical devices of Chinese classes II and III; in vitro diagnostic reagents are explicitly excluded. For class I products, it can serve as methodological orientation without the same submission obligation following from it.
Does every product have to undergo a complete summative evaluation?
That depends on the use risk. For products with high use risk, a validation of the user interface has to be demonstrated, depending on the available data either through a summative usability study or through comparison with an equivalent, already approved product. For products with medium or low use risk, a use error evaluation report is generally sufficient.
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