По честота се дефинират като: много чести (≥1/ 10), чести (≥1/ 100 до < 1/ 10), нечести (≥1/ 1 000 до < 1/ 100), редки (≥1/ 10 000 до < 1/ 1 000) и много редки (< 1/ 10 000) включително отделни съобщения.
Frequencies are defined as: very common (≥ 1/ 10), common (≥ 1/ 100 to < 1/ 10), uncommon (≥ 1/ 1,000 to < 1/ 100), rare (≥ 1/ 10,000 to < 1/ 1,000) and very rare (< 1/ 10,000) including isolated reports.