Data Display
To help make the data easier to understand, we have used the following rules when creating charts. We also include information about each data source, the last update, and the importance of the data with each chart.
Decimals
Numbers are rounded using standard rounding conventions.
- If the value is less than 1.0, we round to two decimal places.
- If the value is greater than 1.0 but less than 10, we round to one decimal place.
- If the value is greater than 10, we show only whole numbers.
- For measures that show observed-to-expected ratios, odds ratios, standardized infection ratios and hours per patient day, we use two decimal places.
- When the data come from a public website, the number of decimal places matches those displayed on the public website.
Y-axis
Data on charts are displayed using a consistent approach to the y-axis values to display the data consistently and realistically.
The y-axis always ranges from zero to a maximum selected according to this logic:
- If the highest data value on the chart is less than 1, the y-axis maximum is 1 and the increment between values is 0.5.
- If the highest data value equals 1, the y-axis maximum is 5 and the increment between values is 1.
- If the highest data value on the chart is between 1 and 2, the y-axis maximum is 5 and the increment between values is 1.
- If the highest data value on the chart is greater than 2, but less than 30, the y-axis maximum is determined by doubling the highest value and rounding to the nearest 10. The y-axis increment is one-fourth or one-fifth of the y-axis maximum.
- If the highest data value on the chart is greater than 30 but less than 100, the y-axis maximum is 100. The increment between values on the y-axis is 20.
- If the highest data value on the chart is greater than 100, the y-axis maximum is determined by doubling the highest value and rounding to the nearest 100. The y-axis increment is one-fourth or one-fifth of the y-axis maximum.
- If the highest data value on the chart is greater than 1000, the y-axis maximum is determined by doubling the highest value and rounding to the nearest 1000. The y-axis increment is one-fourth or one-fifth of the y-axis maximum.
- For measures that have a specific targeted goal, that goal will be the y-axis maximum.
To learn more about public reporting of hospital performance measures, please see the release of "Guiding Principles for Public Reporting of Provider Performance" by the Association of American Medical Colleges.