Table 1.

Classification of the frequency of adverse events.

Very common	⩾1/10
Common (frequent)	<1/10 and ⩾1/100
Uncommon (infrequent)	<1/100 and ⩾1/1000
Rare	<1/1000 and ⩾10,000
Very rare	<1/10,000

CIOMS -Council of International Organizations of Medical Sciences.