There are multiple definitions:

1. Quetelet index(English)

   • BMI

2. quality improvement(English)

   • QA, SQUIRE
   • Quality of life
   • https://doi.org…/09638239917184

3. quality indicator(English)

   • for the evaluation of the care and outcomes for atherosclerotic cardiovascular disease prevention
   • ASCVD, ESAIC
   • Standards, Cardiology, Preventive medicine
   • https://doi.org…/eurjpc/zwab160

4. quadriceps index(English)

   • calculated for isometric quadriceps strength, which is then used to divide the ACL reconstruction participants into high-quadriceps and low-quadriceps subgroups
   • ACL
   • Sports medicine, Knee
   • https://doi.org…363546515602016