A user profile (German: Benutzerprofil) describes the characteristics of an intended user group that are relevant to product use: qualification, experience, training level, physical and cognitive abilities, and possible limitations. It is part of the use specification and the basis for selecting representative participants in usability studies.
What a user profile describes
A useful user profile is specific enough to derive selection criteria for study participants from it. The entry "medical professionals" does not achieve that. It covers occupational groups with completely different training, routine, and responsibility. The following are typically relevant:
- Qualification and expertise: professional degree, specialty, relevant additional qualifications.
- Experience: with the product itself, with comparable products from other manufacturers, and with the underlying therapy or diagnostics. Prior experience with similar devices is ambivalent: It helps, but different operating logic can also lead to errors.
- Training level: whether instruction takes place, to what extent, and how much time typically passes between training and use.
- Frequency of use: daily, occasional, or one-time. A product that someone operates once per quarter places entirely different demands on learnability and recognizability.
- Physical prerequisites: grip strength, fine motor skills, vision and hearing, body dimensions; see ergonomics.
- Cognitive prerequisites and language: understanding of technical language, reading ability, handling of numerical information, available attention in the specific situation.
- Possible limitations: including those related to the indication itself: tremor, reduced sensation, visual impairment, exhaustion, or emotional strain.
The last point is the one most often underestimated. If a product is intended for a condition that typically affects fine motor skills or vision, that is precisely a characteristic of the user profile and not a boundary condition that may be optimistically left out.
User profile, user group, and persona
The three terms are often mixed up but serve different purposes. A user group names who operates a product, for example intensive care nurses or patients in self-use. The user profile describes which characteristics distinguish this group, in a verifiable form. A persona is a design tool: an example figure fleshed out as a narrative that helps a development team keep the user in view.
For regulatory documentation this distinction is essential. Personas are valuable for design but are not evidence documents. They contain freely invented details and cannot be translated into screening criteria. The user profile, by contrast, must be formulated so that an independent party can understand why the participants in a study adequately represent the intended users.
How user profiles are developed
User profiles are developed from the intended purpose (intended use) and then sharpened empirically. The intended purpose defines the indication, patient group, and use environment for which a product is intended; from this follows who will realistically operate it.
Workflow analysis and context analysis provide the concretization: Observation in the real environment regularly shows that people handle the product who did not appear in the original planning. In addition, clinical expertise, experience from post-market surveillance of predecessor products, and findings from known usability problems of comparable devices provide important input.
From profile to participant selection
The user profile is the basis from which the screening criteria for representative users are derived, with explicit inclusion and exclusion criteria. The key principle: The sample must reflect the range of the user group, not its average.
Conducting a study exclusively with experienced, practiced, and highly motivated users is the classic path to an evaluation result that does not hold up in the field. It is precisely the less experienced users, the more occasional users, and the users challenged by limitations who provide the safety-relevant findings. Where several clearly distinguishable user groups exist, each of them must also be considered separately. A mixed sample across heterogeneous groups blurs exactly the differences for which the profiles were separated.
For human factors validation testing, the FDA generally cites at least 15 participants per distinguishable user group. IEC 62366-1 does not specify a minimum number for the summative evaluation. The number of user profiles therefore has direct consequences for study effort and scheduling, which is a reason to cut profiles carefully but not artificially fine.
Typical weaknesses in practice
- One profile for everyone. Heterogeneous groups are lumped together under a collective label even though experience, routine, and tasks differ considerably.
- Forgotten user groups. Service technicians, reprocessing and cleaning staff, and family caregivers interact with the product but do not appear in many use specifications.
- Overly optimistic assumptions about training. Instruction is assumed that in practice does not take place, is shortened, or whose effect has long since faded by the first real use.
- Excluded limitations. Indication-related impairments are not included in the profile even though they are typical for the intended patient group.
- Created once, never reviewed. The profile is defined at the start of the project and not updated against the findings from context and workflow analysis.
Regulatory reference
According to IEC 62366-1, the description of the intended user groups is part of the use specification and thus the starting point of the entire usability engineering process. The FDA Human Factors Guidance expects the participants in human factors validation testing to represent the intended users, including relevant prior experience and limitations, and treats separate user groups as each to be examined independently.
The EU Medical Device Regulation (MDR) requires in Annex I that the design take into account the technical knowledge, experience, education, and training of the intended users, and thus names exactly the characteristics that a user profile documents.
The user profile translates the question "Who uses the product?" into verifiable characteristics and is thus the bridge between the use specification and study recruitment. It must reflect the range of a user group, including less experienced users and indication-related limitations.
A profile cut too coarsely leads to study participants who do not reflect reality, and thus to an evaluation result that does not hold up in the field.
Frequently asked questions (FAQ)
How many user profiles does a product need?
As many as there are user groups with relevantly different characteristics and tasks. What matters is whether qualification, experience, tasks, or conditions of use differ enough that different operating problems are to be expected. Because the FDA considers each distinguishable user group independently in human factors validation testing, the number directly affects study effort.
Do service technicians and cleaning staff count as users?
Yes, provided they interact with the product. Reprocessing, maintenance, calibration, and cleaning are use tasks with their own potential for error. Incomplete reprocessing or incorrectly performed maintenance can be safety-relevant. These groups are regularly overlooked in use specifications.
Do indirect users such as family members or caregivers also belong in the user profile?
Yes. Besides the direct users, secondary users such as family members, care staff, or pharmacists can also interact with the product and cause use errors of their own. These groups should be explicitly considered in the user profile if they are part of the intended use.
Does a persona replace the user profile?
No. Personas are a design tool with narrative, partly invented details. The user profile is a specification document from which verifiable screening criteria must be derivable. Both can coexist, but only the user profile carries weight in regulatory documentation.
How does training affect the user profile?
It must be set realistically. If instruction is assumed, the profile should include the extent to which it actually takes place and how much time typically passes before first use. Because training knowledge fades, it is common to reflect this time gap in the study design as well, rather than testing immediately after instruction.
Do you need study participants who truly reflect your user profile? We recruit healthcare professionals in a structured way, with individual screening and standards-compliant documentation.
More about our recruitmentSources
- IEC 62366-1:2015+AMD1:2020, Medical devices, Part 1: Application of usability engineering to medical devices
- Regulation (EU) 2017/745 on medical devices (MDR)
- FDA Guidance: Applying Human Factors and Usability Engineering to Medical Devices