IX.Add I.4. Methods aimed at specific patient populations

When ICSR databases are sufficiently large, some group of patients may be identified that merit separate attention in signal detection due to known or suspected systematic differences in their responses to medicines. Two such groups that can be differentiated in most databases are the youngest and oldest patients.

A caveat relevant to analyses restricted to any subset of spontaneous ICSRs is that homogeneity of adverse events may be increased resulting in greater potential for masking of signals. For example, analyses within a group of patients who are the main recipients of a class of medicines may not highlight effects related to the entire class. A possible solution is to monitor specific patient groups in parallel to analyses of the total population.