HIV i-Base

Q12H (or q12H) – an abbreviated term for timing medication doses.

q8H means every 8 hours.This is not the same as three times a day (tid or TD).

q12H means every 12 hours. This is not the same as twice-daily (bid or BD).

q24H means every 24 hours. This is not the same as once-daily (qd or QD).

QD (or qd) – a short hand term for medication dosing that means ‘once-daily’.

See also q24H.

qualitative (in a study) – where what is being measured either fits one of several categories, or includes descriptive results.

quantitative (in a study) – where what is being measured has a numerical value or fits a pre-defined scale or range of responses.