What are the 5 Westgard rules?
What are the 5 Westgard rules?
Westgard rules
| Rule | Criteria |
|---|---|
| R4s | Two measurements in the same run have a 4 standard deviation difference (such as one exceeding 2 standard deviations above the mean, and another exceeding 2 standard deviations below the mean). |
| 41s | 4 consecutive measurements exceed 1 standard deviation on the same side of the mean. |
What does a Levey-Jennings chart show?
A Levey–Jennings chart is a graph that quality control data is plotted on to give a visual indication whether a laboratory test is working well. The distance from the mean is measured in standard deviations. It is named after Stanley Levey and E. R.
Which of the Westgard rules is violated in the control data below?
Which of the Westgard multi-rules does the control data violate? The rule broken in the set of control values is the 22s rule. As depicted in the chart, there are two consecutive control values which fall above the 2 standard deviation mark.
How do you implement Westgard rules in a lab?
Best Practices for “Westgard Rules”
- Define the quality that is needed for each test.
- Know the performance of your method (CV, bias).
- Calculate the Sigma-metric of your testing process.
- Relate the QC procedure for the test to the Sigma-performance of the method.
What is Westgard control rules?
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.
Which Westgard rules detect systematic error?
41s rule: This rule applies when four consecutive control samples all exceed the +1 or the -1 limit. The controls could be normal, abnormal, or a combination of the two. This rule detects systematic errors.
What is the purpose of Westgard rules?
What Westgard rules detect systematic error?
How do you do the Levey Jennings chart?
Here are the steps to create a Levey Jennings Chart using QI Macros:
- Click and drag over your data to select it.
- Next, click on the QI Macros menu > Control Charts (SPC) > Special (CUSUM, EWMA) and then on the type of Levey Jennings Chart you want.
What is R 4s rule?
Westgard Rule R. 4s The R4s rule applies to controls within a run. If two controls exceed 4SD, that is, if one control exceeds +2SD and the other control (or another control, if more than 2 controls are tested) exceeds -2SD, the run should be rejected.
What is the 2SD rule?
Westgard rule 22s states that if two consecutive control measurements across runs exceed the same mean -2 standard deviations (SD) or exceed the same mean +2SD, or, within a run, if two consecutive control values are outside the same 2 SD, the run must be rejected.
