SPC Charts Used in Labs
The Levey Jennings chart and Youden plot are popular with lab professionals
- Levey Jennings control chart is used to monitor key measures of health such as cholesterol and glucose.
- Youden Plot is used by labs to compare two runs within the same lab or two runs between labs.
How to Create a Levey Jennings Chart in Excel:
- Organize your data into one column or row
- Click and drag over your data to select it
- Click on the QI Macros menu, then Control Charts, then Levey Jennings chart
- The Levey Jennings chart consists of:
- A line graph of each data point
- An average line
- 1-2-3 standard deviation lines
- Unstable points or conditions will turn red
Learn more about Levey Jennings Control Charts
Here is an example of a Youden Plot comparing five labs who conducted two runs on the same product.
How to Create a Youden Plot using QI Macros Excel template:
- Input the Lab id in column A
- Input data from Run 1 in column B
- Input data from Run 2 in column C
Interpreting the results:
- Lab 4 is biased low.
- Lab 3 had inconsistency between run 1 and run 2.
- Lab 1 has one outlier.