54 клиничните проучвания честотата е дефинирана, както следва: много чести (≥1/ 10), чести (≥ 1/ 100, < 1/ 10), нечести (≥ 1/ 1 000, < 1/ 100), редки (≥1/ 10 000, < 1/ 1 000), много редки (< 1/ 10 000), включващи отделни съобщения.
For clinical trials, the frequency is defined as follows: very common (≥ 1/ 10); common (≥ 1/ 100, < 1/ 10); uncommon (≥ 1/ 1,000, < 1/ 100); rare (≥ 1/ 10,000, < 1/ 1,000); very rare (< 1/ 10,000), including isolated reports.