Ingredient Specific Analyses and Matrix CodeBuilder
An ingredient specific analysis (ISA) is an extension of a menu-level case-control study. In an ISA, exposures are evaluated at the ingredient level (e.g., “romaine”) rather than the menu item level (e.g., “Caesar salad”) during a foodborne outbreak investigation.
An ISA can be instrumental when investigating restaurant subclusters within multistate outbreaks, as it can implicate a particular ingredient.
Steps for an ingredient specific analysis
STEP ONE
Interview cases and controls with restaurant menu
STEP TWO
Gather ingredient information (i.e., build an ingredient matrix to map your menu exposures to ingredient exposures)
- Fill in a matrix
- Use this example file OR
- Get a starter matrix by entering a few items in CodeBuilder App and then download it.
- Gather ingredient data from restaurant employees, a corporate entity, etc.
- Review the ISA Guidance Document for an overview of ISA and to assist with gathering the information at the facility.
STEP THREE
Convert your menu-level exposures to ingredient-level exposures
- The MDH Ingredient Matrix CodeBuilder App can be used to generate R/SAS/Python code.
- Download the CodeBuilder Instruction Protocol
STEP FOUR
Read in outbreak exposure data and run outbreak analysis, including the ingredient-level code.
Stuck? Get help!
If you need assistance conducting an ISA or using the CodeBuilder app, feel free to contact us!
