The European Commission's Medical Device Coordination Group has published guidance on the classification rules for in vitro diagnostics under the incoming regulations.
Under the In Vitro Diagnostic Regulation that takes effect in 2022, IVDs sold in Europe will be put into four risk categories that dictate what requirements apply to them, including whether they need to undergo conformity assessments. The MDCG guidance is intended to help IVD companies identify the right risk category for their products.
MDCG provided seven rules that put IVDs in different risk categories based on how they will be used, as well as principles and other advice to guide companies through the process.
The European Union currently operates a list-based system of IVD classification. Specific IVDs are put onto lists to show the level of risk they pose. IVDR drops that approach in favor of a rule-based model. Manufacturers need to determine where on the spectrum from Class A (low risk) to Class D (high risk) their IVDs fall by assessing their characteristics in light of classification rules.
MDCG set out the rules in a guidance document. As MDCG explains in the document, manufacturers first need to define the intended purpose of their IVDs. How the IVD is supposed to be used, based on its label data, instructions for use and promotional materials, dictates the classification. If an IVD could be used in another, higher-risk way, the instructions for use and technical documentation must clearly limit its application to the intended use that determined the risk classification.
The bulk of the MDCG guidance is given over to a discussion of the seven classification rules. The first rule lists three sets of devices that fall into Class D, the highest risk category. MDCG wants companies to select Class D if their IVDs are used to: detect a transmissible agent in donor materials; detect a transmissible agent that causes a life-threatening disease with a high or suspected high risk of propagation; and to determine the infectious load of a life-threatening disease when monitoring is critical to patient management.
For each subsection of the rule, the guidance provides an explanation and examples. For example, the donor sub-rule states IVDs fall into Class D regardless of whether they are designed to detect transmissible agents within or outside of the scope of a European Union directive on donor testing. MDCG gives hepatitis B and C as well as HIV as examples of transmissible agents that Class D IVDs may detect but stresses the examples given throughout the document are not exhaustive.
The remaining six rules cover the classification of other IVDs, for example by explaining that devices used to detect sexually transmitted agents are Class C and products for general laboratory use are Class A.
Not all IVDs will fit neatly into one category. If multiple rules or sub-rules may apply, MDCG wants manufacturers to "sufficiently" specify the IVD’s intended purpose to "enable a clear attribution of the class." Ambiguity could lead to an IVD being put in a higher risk category.
Other diagnostics use combinations of products. MDCG covers examples of such combinations in an annex, explaining that the analyzer used to run an enzyme-linked immunosorbent assay is Class A but the reagents could be Class B, C or D depending on their intended use.
The risk classifications are a notable departure from current regulations; only Class A IVDs can be self-certified. All other IVDs need to undergo conformity assessments, a new process for many diagnostics, and Class C and D devices are subject to annual surveillance assessments.