Specifications by Measure Category

Almost all technical specifications depend, at least in part, on the category of the specified measure. A calculation algorithm provides a score and derivation of the score determines the measure’s category. 

Determining Measure Categories

Measure Category Process
Ratio The derivation of a ratio’s score is by dividing a count of one type of data by a count of another type of data (e.g., number of patients with central lines who develop infection divided by the number of central line days). The key to the definition of a ratio is that the numerator and the denominator represent the count of different kinds of people, things, events, or objects.
Proportion A proportion is a score derived by dividing the number of cases that meet a criterion for quality (the numerator) by the number of eligible cases within a given time frame (the denominator) where the numerator cases are a subset of the denominator cases (e.g., percentage of eligible women with a mammogram performed in the last year).
Continuous Variable
(CV)
A CV is a score in which the individual value for the measure can occur along a continuous scale and aggregated using a variety of methods such as the calculation of a mean or median (e.g., mean number of minutes between the time when a patient presents with chest pain and the time of thrombolytic medications administration).

Measure Specifications by Measure Category

 

Ratio

Proportion

CV

Target/Initial Population

Required

Required

Required

Denominator

Required

Required

Required*

Denominator Exclusion

Optional

Optional

Optional*

Denominator Exception

Not Permitted

Optional

Not Permitted

Numerator

Required

Required

Not Permitted

Numerator Exclusion

Optional

Optional

Not Permitted

*CV measures may use measure population instead of denominator and measure population exclusion instead of denominator exclusion.

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