### 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). |