# What is Westgard multi rule?

## What is Westgard multi rule?

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.

## How do you use Westgard rules?

Apply the 22s rule within each material across the last two runs; apply the 41s rule within each material across the last 4 runs; apply the 41s rule across the last two runs and the two measurements on each material; apply the 10x rule across the last five runs and the two measurements on each material.

How are Westgard rules 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 are Levey-Jennings charts and Westgard rules?

Levey-Jennings control charts and Westgard rules The material below was modified from the WHO Quality Management Handbook (2011): chapter 7, pages 81-88. Levey–Jennings charts To easily monitor and interpret quality control (QC) data the values of each positive control

### How do you interpret the Levey-Jennings chart?

The control is run in the lab test on a regular basis (e.g., each shift, daily, or before each lab test). Each control result is plotted on the chart. The calculated standard deviation is used to set the control limits. Special rules, called the “Westgard Rules” are used to interpret the Levey-Jennings chart.

### How do you plot control limits on a Levey Jennings chart?

Plot the center line as a sold line on the Levey-Jennings chart and label. Plot the control limits on the Levey-Jennings chart and label. If you are using the Westgard rules (described below), you will also need to plot the lines at +1s, +2s, -1s and -2s from the center line.

What are the rules of Westgard control chart?

Westgard rules include Western Electric rules 1, 2, and 4 and Nelson’s Rule 5. Four points above/below 1 sigma (4 1s) or two points in a row with one above and one below 2 sigma ( R4s ). Westgard rule #9 is unique and is not included in other control chart rule sets.

How many rules does the Westgard scheme have?

The well-known Westgard multirule QC procedure uses 5 different control rules to judge the acceptability of an analytical run.

#### What are the Westgard Sigma rules?

Figure 1 shows the Westgard Sigma Rules for 2 levels of control materials….For example:

• 6-sigma quality requires only a single control rule, 13s, with 2 control measurements in each run one on each level of control).
• 5-sigma quality requires 3 rules, 13s/22s/R4s, with 2 control measurements in each run (N=2, R=1).

#### What is the purpose of Westgard rules quizlet?

What are the Westgard Rules? They are a set of Quality Control Rules, and they are also known as Multi-Rule QC. These rules determine when quality control results are acceptable using the Levy-Jennings charts, and if so patient results are also acceptable.

What is Westgard rules Slideshare?

Follow-up action There are three options as to the action to be taken in the event of a violation of a Westgard rule: • Accept the test run in its completeness – this usually applies when only a warning rule is violated. Reject the whole test run – this applies only when a Rejection rule is violated.

Which of the following Westgard rules is indicative of random error?

13s: This rule applies when a control result falls outside of the 3s limit, either above or below the mean. The run should be rejected. Usually, this indicates that a random error has occurred.

## What is r4s 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.

## Which of the following describes the Westgard multiple 2 2s?

Which of the following best describes the Westgard multirule 22S? Two consecutive data points fall outside +2 SD or -2 SD limits.