Frequency descriptors for events
| CIOMS DESCRIPTOR | FREQUENCY |
|---|---|
| Very common | > 1 in 10 |
| Common | 1 in 10 to 1 in 100 |
| Uncommon | 1 in 100 to 1 in 1000 |
| Rare | 1 in 1000 to 1 in 10 000 |
| Very rare | < 1 in 10 000 |
CIOMS—Council for International Organizations of Medical Sciences.
Data from CIOMS Working Group IV.22