The CT Facility Comparison report compares CTDIvol, Dose Length Product (DLP), and Size-Specific Dose Estimate (SSDE) data for your facility and corporate account with data for all DIR sites. Refer to the DIR Comparison Reports article for an overview of the data contained in the report.

This report is available from the Interactive Reports link under the DIR menu. Although this report is similar to the Facility Excel Report and Corporate Excel Report, this report provides charts and interactive functions to help quickly identify and investigate outlier data.

In addition to the About this Report tab, the report contains three tabs of data

  • Comparison – contains facility or corporate account statistics with comparisons to all DIR sites for each Short Name and Age Group. Data are displayed in both a chart and table, for quick identification of outliers.

  • Exams and Trends – available only via drill-down from the Comparisons tab for a single Short Name and Age Group, this page displays each individual exam for a selected study/age group combination, as well as a trend chart of data by quarter.

  • Short Name Lookups – displays how a facility’s RPIDs map to the Short Name values in the report, as well as how RPIDs for comparison data map to Short Names. This tab also contains the facility’s exam name mappings, i.e. how each study description maps to each RPID for the facility.

To generate the report, select a corporate account from the menu. By default, the report shows data for each facility within the selected corporate account for the most recent quarter available. To switch to corporate account level data, select Corporate Account from the Show Data by the filter at the top of the report. The table in the lower half of the page displays the number of exams and quartiles by Short Nameand Age Group for all DIR sites for the time period specified in the report title. 

DIR CT Facility Comparison Sample 1

The registry data is followed by the exam count and median for each facility with the corporate account. The last column for each facility is a magnitude metric, Facility Median / Registry Median, which reflects how close the facility median is to the registry. Values above 100% indicate the facility median is higher than the registry median, and values less than 100% indicate the facility median is lower. In the example, above, for CT L SPINE WO IVCON Adult (Over 18), the facility median is 38.7 and the registry median is 24.2, resulting in a calculation of 160% (38.7 divided by 24.2). The facility data in the table and chart are color-coded according to the comparison categories displayed in the upper right corner. The table is also sorted to first show the Short Names with facility medians greater than the registry 75th percentile. For corporate accounts with multiple facilities, a single Short Name and Age Group combination may appear multiple times in the table, depending on how each facility’s median compares to the registry's 25th and 75th percentiles.

DIR CT Facility Comparison Sample 2

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The scatterplot is a graphical representation of each facility’s data. Each mark represents a single facility, Short Name, and Age Group combination and is charted using the facility median on the y-axis, and the Facility Median / Registry Median on the x-axis. The vertical line represents the point at which the Facility Median and the Registry Median are the same (Facility Median / Registry Median is 100%). The size of a mark is determined by the number of observations for that facility, Short Name, and Age Group. You can see the details for each mark by hovering over it with your mouse. In the example above, hovering over the red mark in the upper right corner reveals the detailed information for that mark. You can highlight data in the chart and the table. You can also highlight all marks in the Above 75thPercentile category by clicking on the category in the legend. Doing so keeps all related marks in the foreground in the scatterplot, and highlights the relevant cells in the table. Similarly, you can click on a single mark to highlight just that facility’s data for that Short Name and Age Group.

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Report Filters

Several report filters are available to refine the data displayed, including selecting specific facilities, quarters, and DIR measures. Use Display Exams with N >= to filter the chart and table to show exams with a minimum number of observations. By default, the filter is set to only show data for Short Name and Age Group combinations that have at least 25 observations, to help provide more meaningful insights when comparing the data to the registry, but you can also change the filter to start at 1 observation.

DIR CT Facility Comparison Report Filters

Exams and Trends

The Exams and Trends tab contain data for individual exams and long-term trends for a single Short Name and Age Group combination. To navigate to the tab, select a single Short Name / Age Group combination from the Comparisons tab, then click Drill to Individual Exams.

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The report opens the Exams and Trends tab, with a scatterplot of individual exams and a line chart of data by quarter for the selected Short Name and Age Group. The scatterplot shows each study for the time period selected – e.g. the example, below, has one mark for each of the 31 studies for CT L SPINE WO IVCON Adult (Over 18) for the time period 2018 Q3. The title in the scatterplot reads August to September 2018 because there were no studies in July.DIR CT Facility Comparison Sample 6

The colors of each mark represent different facilities, with different shapes for each scanner. You can click on an item in the legend to highlight all of the marks for that particular facility or scanner. You can also use the Keep Only filter to remove all other marks or use the Exclude filter to exclude the selected category and keep all other marks. Use the Undo button, in the lower-left corner, to undo any changes made using the Keep Only or Exclude filters.

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The line chart displays the facility or corporate data trend for all quarters available.  Comparison data for all DIR sites also appear in the charts, with solid horizontal lines indicating the registry median, 75th, and 95th percentiles, to help identify outliers. The dotted line in the scatterplot represents the median for the facility data displayed.

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Short Name Lookups

The Short Name Lookups tab lists each RPID and the Short Name to which it is mapped for the facility and reporting period. The facility’s Study Description is also displayed, reflecting the exam name mapping created for the facility. To see the RPIDs for a specific Short Name, click on the Short Name from the DIR Measures tab, then click on the Look Up Short Name link.

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