Which Westguard rule indicates a systemic (accuracy-based) 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 indicates a systemic (accuracy-based) error?

A systemic (accuracy-based) error shows up as a consistent shift in QC results across a run. The rule that flags four consecutive control measurements on the same side of the mean, each beyond the 1 SD limit, is the one that indicates this kind of bias. It means the process is persistently off in one direction throughout the run, pointing to an accuracy issue such as calibration drift, instrument bias, or a reagent problem. The other patterns indicate different problems: consecutive points beyond ±2 SD can warn of drift, a single point beyond ±3 SD suggests a random outlier, and a pattern like a changing range between adjacent controls points to changes in precision.

A systemic (accuracy-based) error shows up as a consistent shift in QC results across a run. The rule that flags four consecutive control measurements on the same side of the mean, each beyond the 1 SD limit, is the one that indicates this kind of bias. It means the process is persistently off in one direction throughout the run, pointing to an accuracy issue such as calibration drift, instrument bias, or a reagent problem. The other patterns indicate different problems: consecutive points beyond ±2 SD can warn of drift, a single point beyond ±3 SD suggests a random outlier, and a pattern like a changing range between adjacent controls points to changes in precision.

More practice questions