XVI.Add.II.2.7. Spontaneous reporting systems

Interpreting data from spontaneous reporting systems of suspected adverse reactions for the purpose of RMM effectiveness evaluation needs to consider:

• General underreporting of suspected adverse reactions;
• Increased risk awareness due to the RMM or other sources of information (e.g. national information campaign) possibly leading to increased reporting;
• Weber effect, which describes a frequently seen decline in reporting once an adverse reaction of a medicinal product becomes well-known (14); and
• Lack of precise data on the exposure to medicinal products for calculating reporting rates.

Therefore, only comparing trends in spontaneous reporting of suspected adverse reactions for the medicinal product or product class of interest with products used as therapeutic alternatives is not considered adequate for demonstrating RMM effectiveness. However, comparing reporting rates of a specific suspected adverse reaction over time may be useful for RMM evaluation in specific situations. An example of such situation is where the continued spontaneous reporting of a serious adverse reaction with a specifically severe outcome (e.g. adverse pregnancy outcome) supports the evidence from non-interventional studies which indicates that the RMM may not be effective (see XVI.Add.II.3.3. ). Spontaneous reporting may also be useful to identify risk factors for adverse reactions in relation to how medicines are used, e.g. in the context of medication errors. Despite limitations, monitoring trends of spontaneous reporting rates for specific suspected adverse reaction over time (e.g. in annual reports) maybe useful and can under certain circumstances be agreed with the competent authority, e.g. in situations where non-interventional studies are not feasible.