This doesn't really require the usage of the standard template, as it is just a text-error in-game. The item Impatiens reads:

Spell interruption rate -10%
Occ. quickens spellcasting +2%

Every other item in the game that sports a spell interruption rate reduction reads:

Spell interruption rate down X%

So either there is a typo on the Impatiens item or every other item up to the introduction of the Impatiens item that has a the spell interruption rate reduction enhancement is typed incorrectly.