This is the largest study of agranulocytosis. Agranulocytosis tends to occur abruptly within 3 months after initiation of ATD therapy, although it develops gradually in some patients. Providing every patient with sufficient information on agranulocytosis is critical.

B-R assessment can be performed using the BRAT framework with a health care database, but limitations exist when using a single data source. Care should be taken when selecting data for extraction and defining outcomes of interest. Further research is necessary to facilitate practical application of this approach.