It is appropriate to accept the control and report patient results when which Westgard rule is violated?

The 1 2s Westgard rule is used in laboratory quality control to detect systematic errors that might affect the accuracy of test results. Under this rule, if two consecutive control results fall on the same side of the mean and are beyond two standard deviations (2s), it indicates a potential issue with the assay or test system.

However, if this rule is violated — meaning that you do not have two consecutive control results that are beyond two standard deviations on the same side of the mean — it may be appropriate to accept the control results, suggesting there is no strong indication of a system failure. Therefore, when the 1 2s rule is violated, and the controls are still within acceptable limits, it implies that the control is functioning properly, allowing for the reporting of patient results with confidence.

In contrast, violations of other Westgard rules, such as 1 4s or 1 3s, indicate the presence of more significant potential issues with the assay, which would typically lead to a decision to rerun controls or patient samples before reporting. The 2 2s rule relates to issues with too many control results outside the expected range, which again would not allow for acceptable reporting of patient results without further investigation.