Assessing Public Health Laboratory Impact of Salmonella Diagnostic Testing

A man working on his computer at his desk

Quantifying the impact a public health laboratory (PHL) has on an outbreak can be challenging. A new PHL Impact tool gives PHL directors and staff the ability to estimate and illustrate their laboratory’s contribution to and impact of Salmonella diagnostic testing. The tool, developed jointly by CDC and the Association of Public Health Laboratories, uses jurisdiction-specific data to estimate the number of cases, hospitalizations, and total direct medical costs averted due to public health response activities.

How the PHL Impact Tool Works: Data and Results

To use the PHL Impact tool, provide data inputs for up to three example years for nontyphoidal Salmonella burden, PHL throughput, and costs associated with diagnostic testing. Input jurisdiction-specific estimates for five categories of data: epidemiology, medical costs, laboratory testing, laboratory costs, and outbreak response activities. PHL Impact tool uses these inputs to produce several types of results:

  • Burden of nontyphoidal Salmonella
  • Outbreak response activities
  • Volume of specimens and isolates tested by the public health laboratory
  • Total and average (per case) direct medical costs associated with Salmonella outbreak(s)
  • Total and average (per specimen/isolate) laboratory testing costs associated with Salmonella outbreak(s)

With the PHL Impact tool, users also have the option to develop up to two illustrations of response impact by providing information about one or two selected Salmonella outbreaks and associated response activities within their jurisdiction. After using the tool to generate findings, users can create a report to describe their PHL’s contribution to and impact on Salmonella diagnostic testing. Estimates derived by the tool should not be considered forecasts of what will occur.

Getting Started with the Public Health Laboratory Impact Tool

Download the Tool, User Manual, and Report Template

We recommend downloading and saving the PHL Impact spreadsheet to your computer and then opening the spreadsheet from your computer. This will allow the spreadsheet to open in Excel instead of your web browser.

Load, Start, and Navigate

  1. Open the PHL Impact tool spreadsheet and click the box at the top of the spreadsheet that says “Enable Macros,” or “Enable Content” (depending on the version of Excel being used).
  2. After enabling macros, click the “Start” button on the cover page to start navigating the tool.

If you encounter any issues, contact with a subject line [PHL Impact tool inquiry].

Changing Input Variables

When you download and open the PHL Impact tool spreadsheet, some inputs are pre-populated with numbers and estimates based on published sources. Users can change the values in the yellow cells in the tool to best illustrate Salmonella burden, direct medical, and laboratory testing costs in their jurisdiction. Further, we encourage users to enter a range of values to explore the impact of year-to-year variability. A user can, in the tool, click icon buttons at the top right corners of each page to see variable definitions and explanations. Additional explanations are provided in the accompanying manual.

System Requirements to Use PHL Impact Tool

PHL Impact tool uses the Windows* operating system (Microsoft Windows 2010 or higher) and Excel (Microsoft Office 2013 or higher). Full functionality of the tool is supported in the desktop version of Microsoft Office® for Windows. Some functionality may not be available in Microsoft Office for Macs or in the browser version of Office 365.

*Microsoft Windows and Office are copyrighted products produced by Microsoft Corporation, WA. The use of trade names and commercial sources is for identification only and does not imply endorsement by the U.S. Department of Health and Human Services.