How are Westgard Rules calculated?

To calculate cumulative control limits, enter the previous month’s figures for n, sum of x, and sum of x squared, then push the “Total” button. To calculate monthly control limits, just push the “Total” button and only the monthly figures will be used.

How is QC percentage calculated?

It is calculated by taking the difference between the control result and the expected mean, then dividing by the standard deviation observed for that control material.

What is Westgard Multirule?

Westgard Rules are multirule QC rules to help analyze whether or not an analytical run is in-control or out-of-control. It uses a combination of decision criteria, usually 5 different control rules to judge the acceptability of an analytical run.

What is a Multirule QC?

A multirule QC procedure uses two or more statistical tests (control rules) to evaluate the QC data, then rejects a run if any one of these statistical tests is positive.

How do you establish quality control ranges?

There are 4 main steps involved in assigning accurate targets and ranges:

1. Establishing Mean Target Values using Parallel Testing.
2. Calculating Historical CV (CVh)
3. Determining Appropriateness of Calculated CVh.
4. Establishing QC Ranges using CVh.

What to do if QC is out of range?

If the repeat value is still out of range, run a new vial of control. If the new control value is within acceptable limits, record the values and proceed with patient testing. The problem with the first set of controls was probably specimen deterioration.

What are the warning Westgard rules?

One measurement exceeds 2 standard deviations either above or below the mean of the reference range. One measurement exceeds 3 standard deviations either above or below the mean of the reference range.

What is R 4s rule?

The R 4s rule identifies random error. It is applied only within the current run. This rule is violated when there is at least a 4SD difference between control values within a single run. For example, assume both Level 1 and Level 2 have been tested within the current run.

How are the Westgard rules used in multirules?

In the original Westgard multirule QC procedure, this rule is used as a warning rule to trigger careful inspection of the control data by the following rejection rules. 22s – reject when 2 consecutive control measurements exceed the same mean plus 2s or the same mean minus 2s control limit.

How are control rules used in multirule QC?

Multirule QC uses a combination of decision criteria, or control rules, to decide whether an analyticalrun is in-control or out-of-control. The well-known Westgard multirule QC procedure uses 5 different control rules to judge the acceptability of an analytical run.

Where can I find a Westgard calculator on my computer?

Following the link at the bottom will take you to a special area of Westgard Web for calculators and plotters. All of the formatting, menu tabs, side links, and so forth will disappear; all you will see is the form where you enter numbers and select options.

Is it mrs.westgard’s rules that really count?

I will also have to admit that around our house it is Mrs. Westgard’s rules that really count. My wife Joan hates it when I tell this part of the story, but she’s put up with me for over thirty-five years and I’m now in a state of fairly stable control, so it will take a bigger deviation than this before I get into big trouble.

https://www.youtube.com/watch?v=PmZd1UbP55c