If one control is outside the 95% confidence limits, what is the most appropriate initial remedial action?

When a control is outside the 95% confidence limits, the most appropriate initial remedial action is to repeat the same control. This is a standard procedure in quality control because it allows the technologist to determine whether the out-of-control situation was due to a random error or if it indicates a systemic issue with the testing process.

By repeating the control, the medical technologist can verify the reliability of the initial result. If the repeated control falls within the established confidence limits, it suggests that an isolated error may have occurred. However, if the repeated control is still outside the limits, it indicates a consistent problem that may require further investigation.

In contrast, other actions such as discarding the results, changing the assay method, or informing the supervisor are premature at this stage. Discarding results without verifying them may lead to the loss of important data, and jumping to change the assay method could overlook potential transient issues that might resolve upon retesting. Informing the supervisor is appropriate as a subsequent step, but the immediate focus should be on confirming the accuracy of the control result through repetition.