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Measure Specification

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

The table defines the components relevant for the three measure categories. 

 

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 use measure population instead of denominator and measure population exclusion instead of denominator exclusion.

Last Updated: Oct 2022