The use specification describes the essential characteristics of the intended context of use of a medical device. It summarizes the properties of patients, users, use environments and the medical field of application that are relevant for safe use.
According to IEC 62366-1, the use specification is created early in the usability engineering process. It forms an essential basis for identifying safety-related characteristics of the user interface, foreseeable use errors, use-related hazards and hazard-related use scenarios.
Role in the usability engineering process
The use specification is one of the first results of the usability engineering process. It defines the framework within which the safety-relevant characteristics of the user interface, possible use errors, hazards, hazardous situations and hazard-related use scenarios are identified.
Errors, unsubstantiated assumptions or gaps in the use specification can affect all subsequent process steps, from the use-related risk analysis through the development of the user interface to formative and summative evaluation.
Because the use specification describes the intended use of the medical device, it serves as the central reference basis for many subsequent activities. Changes to the product concept, the intended patient groups, user groups, use environments or use scenarios must therefore be checked for their effects on the use specification and the usability engineering process.
Typical contents of a use specification
IEC 62366-1 names key information that must be defined in the use specification. This includes in particular:
- Medical indication and intended medical field of application
- Intended patient group
- Intended body area or tissue type, where relevant
- Intended user groups and user profiles
- Intended use environments
- Operating principle of the medical device
Depending on the product and the associated risks, this information should be made more specific. Typical supplementary contents are:
- Use goals and essential tasks of the users
- Frequency and duration of use
- Required education, experience and training
- Physical, sensory and cognitive characteristics of the users
- Language skills, health literacy and technical prior knowledge
- Relevant device states and use workflows
- Maintenance, cleaning, reprocessing, installation and service
- Accompanying documentation and support materials used
- Environmental conditions such as lighting, noise level, space conditions or distractions
- Special conditions such as stress, time pressure, emergencies or limited attention
Especially for products for home use, less controlled conditions of use must also be taken into account. These can include, for example, changing lighting conditions, limited space, distractions, the presence of other people or a lack of immediate support from medical professionals. The FDA likewise regards users, use environment and user interface as the three central components of a device-user system.
Delimitation from related documents
The use specification is often confused with the intended use (in the MDR: intended purpose). The two documents overlap but serve different functions.
The intended use describes in particular the intended medical purpose of the product. This includes, for example, the medical indication, the patient group and the diagnostic or therapeutic function.
The use specification takes up this information and makes it more specific from the perspective of actual use. It describes in particular:
- who uses the product,
- which prerequisites and limitations these people have,
- in which environments the product is used,
- which tasks are performed and
- which conditions of use have to be taken into account.
The use specification must also be distinguished from user requirements or user needs. User needs describe needs, expectations or goals of the users. The use specification, by contrast, first describes the intended context of use and the relevant characteristics of patients, users and use environments. Concrete user and product requirements can subsequently be derived from this information.
| Document | Describes |
|---|---|
| Intended use (intended purpose in the MDR) | The intended medical purpose of the product, for example the medical indication, the patient group and the diagnostic or therapeutic function |
| Use specification | The actual use: who uses the product, which prerequisites and limitations these people have, in which environments it is used, which tasks are performed and which conditions of use have to be taken into account |
| User requirements (user needs) | Needs, expectations or goals of the users |
Link to the use-related risk analysis
The quality of the use-related risk analysis depends substantially on the completeness and accuracy of the use specification.
Only when the relevant user groups, environmental conditions, tasks and use workflows are known can foreseeable use errors and their possible consequences be analyzed systematically. For example, different risks can arise:
- with professional users and medical lay persons,
- with different levels of education or experience,
- in the operating room and in the home environment,
- in routine use and in emergency situations,
- during the actual use and during cleaning, reprocessing or maintenance,
- under normal conditions and under stress, time pressure or high workload.
A use specification that is too coarse can lead to relevant use errors or hazard-related use scenarios being recognized only in late development phases or during the summative evaluation. This can make additional design changes, repetitions of evaluations or regulatory queries necessary.
Methods for creating and reviewing it
The use specification should not be based exclusively on assumptions of the development team. Its contents should be derived traceably from suitable information sources and empirical findings. Suitable methods and sources are, for example:
- Context analyses
- Stakeholder and user interviews
- Field observations
- Contextual inquiry
- Task analysis
- Workflow analyses
- Literature and market analyses
- Manufacturer information on comparable products
- Complaints, incidents and vigilance data
- Findings from formative evaluations
- Feedback from service, training and application support
The use specification is not a document that is completed once. Especially for innovative products or new use contexts, it is often made more specific iteratively. New findings from research, development, risk management or formative evaluations should be checked to see whether an update is required.
Not every single statement has to be substantiated by a study of its own. The underlying assumptions should, however, be comprehensible, plausible and appropriately secured. The higher the use-related risk and the more novel the product or use context, the more important robust empirical findings are.
Typical weaknesses in practice
A frequent mistake is to describe user groups too generally, for example merely as “medical staff”. As a result, relevant differences in education, experience, tasks, authority or physical and cognitive prerequisites remain unconsidered. Further typical weaknesses are:
- Mixing up intended use and use specification
- Incomplete description of the intended patient groups
- Missing differentiation of relevant user groups
- Purely demographic instead of task-related user profiles
- Missing consideration of foreseeable use situations
- Neglect of installation, maintenance, cleaning and reprocessing
- Insufficient description of home use scenarios
- Missing consideration of stress, time pressure, distraction or emergencies
- Assumptions without a comprehensible justification
- Missing link to the use-related risk analysis and use scenarios
- Missing update when product or process changes occur
In audits and regulatory reviews, use specifications can be particularly problematic if they contain only generic information or show no comprehensible link to the use scenarios analyzed and evaluated later.
Regulatory reference
IEC 62366-1 requires the creation of a use specification as the first substantive step of the usability engineering process. On this basis, safety-relevant characteristics of the user interface, foreseeable use errors, hazards, hazardous situations and hazard-related use scenarios are subsequently identified.
The informative report IEC 62366-2 contains supplementary explanations, examples and methods for the practical implementation of usability engineering.
The FDA also expects an appropriate description of the intended users, uses and use environments. This information forms an essential basis for planning human factors activities and for assessing whether a medical device can be used safely and effectively by the intended users.
In risk management according to ISO 14971, information on users, contexts of use and foreseeable conditions of use are important inputs for identifying hazards, hazardous situations and use-related risks.
The use specification creates the common and comprehensible basis for all use-related activities in the development process. It defines for whom, for what, where and under which conditions a medical device is to be used.
Anyone who describes user groups, patient groups or use environments too coarsely risks gaps that continue from the use-related risk analysis through the design of the user interface into the summative evaluation.
Frequently asked questions (FAQ)
Is the use specification identical to the intended use?
No. The intended use primarily describes the intended medical purpose of the product. The use specification takes up this information and supplements it in particular with user profiles, use environments, tasks, workflows and further relevant conditions of use.
Does the use specification have to be substantiated empirically?
The standard does not require separate empirical evidence for every single statement. The contents and underlying assumptions must, however, be comprehensible and appropriately justified. The higher the risk or degree of innovation of the product, the more important empirical data from the actual or a comparable context of use are.
When should the use specification be updated?
The use specification should be updated when relevant information on the product, intended use, patient group, user groups, use environments or use scenarios changes. Findings from risk management, complaints, post-market surveillance or formative evaluations can also make an adjustment necessary.
Are user profiles and the use specification the same thing?
No. User profiles are one component of the use specification. The use specification also comprises, among other things, the medical indication, patient groups, use environments, conditions of use and the operating principle of the medical device.
Do you want to create the use specification for your medical device in a regulatory-robust and practical way? We support you throughout the usability engineering process according to IEC 62366-1.
More about our usability engineeringSources
- IEC 62366-1:2015+AMD1:2020, Medical devices, Part 1: Application of usability engineering to medical devices
- IEC/TR 62366-2:2016, Medical devices, Part 2: Guidance on the application of usability engineering to medical devices
- ISO 14971:2019, Medical devices, Application of risk management to medical devices
Related terms
- Context of use
- Use-related risk analysis (URRA)
- User profile
- Use scenario