were applied for the interpretation of daily internal quality control results.
Examples include QA on reagents, lot numbers, expiration dates, testing accuracy, Westgard rules
, and test results directly incorporated into the laboratory information system (LIS) which are stored directly within the patient case.
Quality control was ensured using internal quality control kits, Levey-Jennings charts based on lab-derived mean and standard deviation, corrective action on violations of Westgard rules
, and subscribed external quality controls.
Linnet has compared a "mean rule," closely related to Stouffer method, with traditional Westgard rules
. Given the same type-I error, the mean rule was more powerful for detection of shifts of location than Westgard rules
On applying Westgard rules
on the internal quality control data of protein all runs were acceptable at both control levels.
Sophisticated user-definable display of QC results should include Levey-Jennings plots and interactive display of violations of user-selected rules, such as Westgard rules
. Available: http://www.westgard.com/westgard-rules [accessed 4 February 2010].
Mention is made of Levey-Jennings charts and Westgard Rules
but there is really no mention of how to use these tools in the context of day-to-day blood gas laboratory operation.
With advanced middleware solutions, laboratorians can set rules, defining QC protocols for each analyte based on QC metrics such as Westgard rules
. Trained laboratory staff members can set middleware rules that inform all staff of QC issues, or automatically stop autovalidation.
Usually, this is done in conjunction with what's called the Westgard Rules
, which are a convention that an instrument run and all its results should be scrutinized if any one control exceeds 2s from the mean (known as a 1(2s) violation).