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Jul 7, 2014

Reducing the time it takes to investigate Salmonella cases

Not only is rapid response by public health authorities to Salmonella cases comforting to the community, but it is also critical to containing the spread of the disease to reduce the likelihood of an outbreak.

“Time to investigation,” or how long it takes to investigate a reported Salmonella case, is a key performance metric for the Communicable Disease Prevention & Control program at Santa Clara County Public Health Department in California. To identify the root causes of “slow down” in the response time for Salmonella cases, the department put together a Six Sigma project team to tackle the problem.

I was fortunate to be able to work with the team on getting up to speed in using JMP to handle the analysis needs for the project. I saw firsthand how team members were able to use data to substantiate a change. During the measure and analyze phase of the project, the team established a baseline for time to investigation using control charts in JMP. For their baseline from January to March 2015, the average time to investigation for Salmonella cases was 23.8 hours.

To analyze the barriers significantly associated with time to investigation, the team used the Fit Model platform in JMP. From the baseline period, barriers that were significantly associated with time to investigation for Salmonella cases included problems locating the physician, the volume of reports and staff assigned to advice calls.

Changes were implemented in April 2015. By May 2015, the average time to investigation for Salmonella cases was 11.7 hours, a 50% decrease in time. Team members were able to see and visually communicate the difference using control charts in JMP.  The control charts are posted online.

The program is continuing the Six Sigma project by monitoring data for time to investigation and barriers to investigation. A report of this work was recently published on the Public Health Quality Improvement Exchange (PHQIX). PHQIX is an online community for public health professionals to share information about quality improvement in public health.

The full story is available online at PHQIX.