Intended purpose and intended use: More consequences than you think!

The correct and precise formulation of the intended purpose of medical devices and in vitro diagnostic medical devices (IVD) is crucial for their successful development and approval. However, even the definitions of terms and the distinction between intended purpose and intended use make it difficult to achieve clarity and precision.

This article reveals how to formulate an intended purpose to avoid difficulties during audits and approvals.

1. Relevance of the intended purpose

With the intended purpose, the manufacturer expresses the (medical) purpose for which he wants his device to be used. This definition is the prerequisite for many activities during development and approval:

• Qualification of the device, i.e., the decision as to whether it is a medical device or an IVD
• Classification of the medical device/IVD in accordance with the MDR or IVDR
• Deciding which standards must be taken into account during product development
• Specification of the device and its performance parameters
• Delimitation of normal and abnormal use (derivation of the use specifications)
• Product-specific risk management (risk management plan including derivation of the risk-acceptance matrix and risk analysis)
• Performing the clinical evaluation or performance evaluation, which must demonstrate that the purpose and medical benefit have been met
• Writing the post-market surveillance plan, which defines how achievement of the intended purpose will be monitored in the field

It is the task and freedom of the manufacturer to determine the intended purpose.

2. Definitions of the term “intended purpose”

This chapter introduces the relevant definitions. The next chapter delimits intended purpose and intended use.

a) Definition according to the MDR or IVDR

In addition to the term “intended purpose,” the MDR/IVDR also uses the term “intended use.” However, neither regulation defines this term.

b) Definition in IEC 60601-1

IEC 60601-1 defines the term “intended purpose” as “use for which a product, process or service according to the specifications, instructions and information provided by the manufacturer” (IEC 60601-1:2005, 3.44).

c) Definition in ISO 14971

ISO 14971 has revised the definition of the term in its third edition (ISO 14971:2019). However, it equates intended use and intended purpose. But the annotation indicates that rather the medical purpose is meant.

d) Definition by the FDA

The FDA defines the term “intended use” in 21 CFR part 801.4 as follows:

3. Distinction from intended use

Strictly speaking, the term “intended purpose” in the broader sense covers several aspects in the case of medical devices and IVD medical devices:

1. The actual medical purpose (“intended medical purpose” or intended purpose in the narrower sense), i.e., what disease or injury is intended to be diagnosed, treated, or monitored.
2. The medical use determines the medical context, i.e., which users in which context of use are to use the device for which patients.
3. The (additional) intended use, which determines what can be done with the device as a whole or in addition to it. This includes storing, transporting, updating, or cleaning the device.

The MDR and IVDR refer to “normal use” instead of “intended use.” Both terms are to be understood synonymously.

4. Regulatory requirements

There are several regulations that you should consider in this context:

1. The MDR and the IVDR require the intended purpose to be specified in the technical documentation (see chapter 5).
2. ISO 13485 requires in 7.3.7: “Design and development validation shall […] ensure that the resulting product is capable of meeting the requirements for the specified application or intended use.” This presupposes that these are known.
3. ISO 14971, the harmonized standard for risk management, requires the intended purpose for further risk analysis in chapter 5.2.
4. IEC 62366-1 requires the creation of a “use specification” in chapter 5.1, the summary of which is referred to by some authorities as the intended purpose.
5. IEC 60601-1 requires a precise specification of the application environment, which includes physical parameters such as temperature, altitude/air pressure, brightness, supply voltage(s), and the degree of contamination.

5. Contents of an intended purpose

5.1 Intended purpose of a medical device

Based on MDR Annex I, Chapter III, 23.4 b) and Annex II 1.1 a), address the following aspects in your intended purpose:

• Medical purpose: What disease or injury is to be diagnosed, treated, monitored, alleviated, or predicted?
• Medical indication and contraindication
• Intended patient group(s)
• Intended body part
• Intended users
• Intended use environment
  • Physical environment, e.g., brightness, noise, contamination
  • Social environment, e.g., stress, shift work
  • Technical environment, e.g., tools, software
  • Clinical environment, e.g., sterile, wear of protective equipment
• Functionality

5.2 Intended purpose of an IVD medical device

The contents of the intended purpose of an IVD are clearly specified in Annex I, Chapter III, 20.4.1 c) and Annex II 1.1 c) of the IVDR. The intended purpose of an IVD medical device includes:

• What is detected and/or measured;
• Its function (e.g., screening, monitoring, diagnosis or diagnostic aid, prognosis, prediction, companion diagnostic);
  • Note: The definitions in the guidance document GHTF/SG5/N8:2012 are helpful in determining the function of an IVD medical device.
• Specific information to be provided in the following contexts:
  • Physiological or pathological state;
  • Congenital physical or mental impairments;
  • Predisposition to a medical condition or a disease;
  • Determination of the safety and compatibility with potential recipients;
  • Prediction of treatment response or reactions;
  • Definition or monitoring of therapeutic measures;
  • Whether it is automatic or not;
  • Whether it is qualitative, semi-quantitative, or quantitative;
  • The type of specimen(s) required;
  • The testing population, if applicable
  • The intended user and;
  • in the case of companion diagnostics, the International Non-Proprietary Name (INN) of the associated medicinal product.

Manufacturers of medical devices and in-vitro diagnostic medical devices usually also subsume the other intended use in the intended purpose document.

6. Avoid pitfalls

a) Inconsistent formulation of the intended purpose

The intended purpose of a device is the central starting point for many subsequent processes, as the list in chapter 1 shows. During reviews of technical documentation, we repeatedly find that the intended purpose is formulated inconsistently in the various documents. As a result, not all the necessary evidence may be provided in the clinical or performance evaluation, and the notified bodies may not accept the technical file.

We recommend to set up your technical documentation based on data rather than documents to avoid redundancies and inconsistencies. Our article, 7 tips for the successful digital transformation of medical device manufacturers, provides an initial insight.

Please also note that information on the intended purpose must be consistent in the technical documentation, the associated marketing material, and the website.

b) Claims that have not been proven

Manufacturers of medical devices and in-vitro diagnostic medical devices use the intended purpose to claim the (medical) benefit of their devices.

The MDR defines clinical performance in Article 2 (52) as “the ability of a device, resulting from any direct or indirect medical effects which stem from its technical or functional characteristics, including diagnostic characteristics, to achieve its intended purpose as claimed by the manufacturer, thereby leading to a clinical benefit for patients, when used as intended by the manufacturer;” The IVDR defines the “performance of a device” as “the ability of a device to achieve its intended purpose as claimed by the manufacturer. It consists of the analytical and, where applicable, the clinical performance supporting that intended purpose;” (IVDR Article 2 (39)). “Clinical performance,” as part of the performance of a device, is defined as “the ability of a device to yield results that are correlated with a particular clinical condition or a physiological or pathological process or state in accordance with the target population and intended user;” (IVDR Article 2 (41)).

This means that manufacturers must demonstrate the clinical benefit of their device, which they state in the intended purpose, through the clinical evaluation or performance evaluation. Manufacturers should also consider the defined patient population, the intended users, and the intended use environment. Thus, the intended purpose has a direct influence on the scope of the clinical evaluation or performance evaluation and the associated effort.

For example, manufacturers could initially limit the intended purpose to a specific patient population to reduce the effort involved in the clinical or performance evaluation. After establishing the device on the market, the manufacturer can expand the intended purpose with the underlying clinical evidence.

7. Conclusion

The intended purpose is the basis for developing your medical device or IVD. If it is missing, incorrect, incomplete, inconsistent, or incomprehensible, you are likely to encounter more than just regulatory problems during development. Typically, auditors and inspectors read this document at the very beginning. So, take the time to create it carefully!

---

Change history:

• 2024-08-12: Fundamental revision of the article; mainly integration of IVD medical device-relevant information
• 2021-03: Article completely revised; especially the introduction and chapter 3 (definitions) supplemented and updated