---
title: "Measure categories"
slug: "glossary-measure-categories"
updated: 2023-03-23T19:38:29Z
published: 2023-03-23T19:38:29Z
canonical: "docs.ursahealth.com/glossary-measure-categories"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ursahealth.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Measure Categories

In Ursa Studio there are two primary categories of measures – population and performance.

## Population measures

Population measures are measurements of the quantity (count) of a body of persons or events that have a quality or characteristic in common. For example, the count of active plan members across a certain span of time.

Population measures enable users to explore the properties associated with a group of entities or events. These measures are also useful for quantifying numerator and denominator observations associated with performance measures. While population measures do not have a native numerator, Analytics Portal’s Measure Expression feature enables users to plot any numeric field associated with a population measure as a numerator, which creates a proper rate measure.

#### Count of Active Plan Members

![Measure categories_population measures.png](https://cdn.document360.io/02092ce8-55b8-4ac5-9554-c0ccb3223feb/Images/Documentation/Measure%20categories_population%20measures.png)

## Performance measures

Performance measures are measurements of the rate - an amount, ratio, or degree - of something measured per unit of something else. For example, the rate of blood stream infections occurring after seven days of inpatient care.

A performance measure is a numerical expression resulting from a numerator-denominator relationship that represents a real-life circumstance. The measure’s denominator defines the scope of a performance opportunity (e.g., hospital inpatient stays lasting longer than 7 days). The measure’s numerator defines the realization of performance within that opportunity (e.g., the inpatient stays lasting longer than 7 days where the patient developed a blood stream infection).

#### Among hospital admissions with a LOS > 7 days, the percentage of those where the patient developed a blood stream infection (BSI)

![Measure categories_performance measures.png](https://cdn.document360.io/02092ce8-55b8-4ac5-9554-c0ccb3223feb/Images/Documentation/Measure%20categories_performance%20measures.png)