Which Westguard rule among the following is used to indicate systemic error?

Prepare for the CAMLPR Chemistry Test. Enhance your understanding with interactive quizzes, flashcards, and detailed explanations. Boost your confidence and readiness for exam success!

Multiple Choice

Which Westguard rule among the following is used to indicate systemic error?

A pattern where many control measurements drift in the same direction within a single run signals a bias or systemic error in the process. The rule that best captures this is the one requiring four consecutive control results to exceed the mean by more than 1 standard deviation on the same side. When you see four in a row all high or all low by at least 1 SD, it shows a persistent shift rather than random scatter, indicating systematic error in the method, instrument, or reagents. Two consecutive results beyond 2 SD on the same side points to unusual variation but isn’t as directly tied to a consistent bias across the run. The rule that looks at the range between two adjacent results exceeding 4 SD flags instability within the run (imprecision or outliers) rather than a steady bias. The mixed pattern where one value goes beyond 1 SD and the next beyond 3 SD is a warning signal and not as definitive for a sustained bias as the four-in-a-row 1 SD pattern. So, the rule that indicates systemic error is the one describing four consecutive results beyond 1 SD on the same side.

A pattern where many control measurements drift in the same direction within a single run signals a bias or systemic error in the process. The rule that best captures this is the one requiring four consecutive control results to exceed the mean by more than 1 standard deviation on the same side. When you see four in a row all high or all low by at least 1 SD, it shows a persistent shift rather than random scatter, indicating systematic error in the method, instrument, or reagents.

Two consecutive results beyond 2 SD on the same side points to unusual variation but isn’t as directly tied to a consistent bias across the run. The rule that looks at the range between two adjacent results exceeding 4 SD flags instability within the run (imprecision or outliers) rather than a steady bias. The mixed pattern where one value goes beyond 1 SD and the next beyond 3 SD is a warning signal and not as definitive for a sustained bias as the four-in-a-row 1 SD pattern.

So, the rule that indicates systemic error is the one describing four consecutive results beyond 1 SD on the same side.

More practice questions