We are receiving a lot of questions about relevant analyses in the Analyse-it Method Validation edition to help in evaluating new diagnostic tests in the fight against COVID-19. Below are some quick links that will help, but contact us if you have questions - we are working as normal.
Also see our latest blog post: Sensitivity/Specificity and The Importance of Predictive Values for a COVID-19 test
Effective use of control charts requires periodic revision of control limits when
changes to the process cause a reduction in variability or shift to a new operating
The standard Shewhart control limits are good at detecting large shifts but are
not sensitive to smaller shifts. Applying advanced out-of-control rules has
identified a shift to a new process mean towards the end of the installation period
suggesting that the process was moving to a new phase.