American Society for Clinical Pathology (ASCP) Histotechnician Certification Practice Exam

What will the on board controls (OBC) do when testing for prothrombin time (PT) with a point of care (POC) instrument?

1. Need to be replaced frequently

2. Be documented manually

3. Be accepted by a bar code range

4. Be ignored during testing

The correct answer is: Be accepted by a bar code range

The on board controls (OBC) serve a critical function in the testing process for prothrombin time (PT) using point of care (POC) instruments. These controls are integral to ensuring the accuracy and reliability of test results. When a POC instrument performs a test, it is crucial that it verges within established calibration limits or ranges, which is where the acceptance of controls comes into play. By being accepted by a bar code range, the OBC allows the system to automatically verify that the results obtained are within the expected thresholds before proceeding with patient results. This automated acceptance helps in minimizing the risk of human error and ensures that any deviations are flagged for further review. Given the nature of point of care testing, which is often performed in non-laboratory settings, the reliance on such automated controls increases the confidence in the results being produced. The other options lack relevance in the context of the operational protocols for POC testing. Frequent replacement of controls, manual documentation, or ignoring controls during testing do not align with the best practices designed to maintain the integrity of patient testing outcomes. Thus, acceptance by a bar code range stands out as the most reliable approach for validating the OBC during PT testing.