What are primary users? What are secondary and even tertiary users? What specific requirements do regulations place on these user types, particularly the FDA and IEC 62366? Should we talk about users, operators, or consumers? This article provides answers.
1. Primary users, secondary users, and indirect users
a) Primary users
Primary users are the users of a product who use it to achieve a medical purpose. Examples include physicians, nurses, and medical assistants.
b) Secondary users
Secondary users are users of a product who use it for other typical uses. These include, for example, service technicians and persons responsible for installation, updating, and configuration.
c) Indirect or tertiary users
Indirect or tertiary users are persons who need the deliverables, particularly those of primary users, for their own work. For example, a medical controller needs the ventilation hours recorded by another user (primary user) in the medical information system to bill a hospital stay.
2. Regulatory Requirement
a) Characterization of primary users and secondary users
Neither the FDA nor IEC 62366 differentiates between these user types. Neither imposes any requirements on tertiary users. However, the FDA and IEC 62366 require you to characterize all users, primary and secondary users. You can characterize users based on
- Education, experience in the relevant (medical) context
- Experience with the product or products of the same product class
- Typical tasks
- Demographic characteristics such as age and gender
- Mental and physical abilities or limitations
- Social and cultural background
b) Further Requirements
The FDA requires that primary and secondary users be considered when specifying the user interface.
The IEC 62366 also requires the same and defines the primary operating functions as safety-critical and frequently used.
- It is usually the frequently used functions that primary users use.
- Safety-critical functions exist for both primary and secondary users. Medical device manufacturers regularly overlook the fact that configuration—a task primarily performed by secondary users—is rarely carried out, but that errors can have serious consequences, i.e., they are safety-critical.
3. User, operator or user
Are users, operators, and consumers the same thing? Which of these terms should be used? My usability guru, Thomas Geis, provides a clear answer: The term user is the one you should use. Why? There are several reasons for this:
- The standards use this term. They don’t just talk about users, but also about user scenarios, user interfaces, and user profiles. Operator-product interface would also sound strange.
- The term “operator” implies that both the person and the machine are being operated. Hopefully, we are not there yet.
- The term “user” is already used for the “using organisation.” For example, Lufthansa uses SAP.
But be careful: It is not user error but usage error. It is not the user who has made a mistake; rather, an error occurred during use.
