they are specific terms using in this subject.

disease specific measure, Comorbidity, general measure

to measure comorbidity, we can use general measure (1st option), general measure + additional indicator (such as gender, geogrophical region etc..), disease specific measure.

Measure can be verb, or Noun. In some case, measures(noun) can be replaced with instruments(noun), but have to be very cautious for the replacement. It may lead to wrong interpretation if you don't fully understand the situation.