Which final result category would indicate the result is invalid due to procedural or instrument failure?

Which final result category would indicate the result is invalid due to procedural or instrument failure?

• A. Negative
• B. Positive
• C. Inconclusive
• D. Invalid

Answer: (D)

When a test run is compromised by a problem with the process or the instrument, the result cannot be trusted and is labeled as invalid. This category exists specifically to indicate that the entire measurement is unusable because QC criteria were not met or the instrument failed (calibration errors, downtime, procedural mistakes, etc.), so a repeat test is required after the issue is resolved. In contrast, a negative result means no detectable analyte was found and the test ran under valid conditions; a positive result means the analyte was detected; and an inconclusive result indicates ambiguity in the outcome even though the run completed, but not necessarily due to a clear instrument or procedure failure.

When a test run is compromised by a problem with the process or the instrument, the result cannot be trusted and is labeled as invalid. This category exists specifically to indicate that the entire measurement is unusable because QC criteria were not met or the instrument failed (calibration errors, downtime, procedural mistakes, etc.), so a repeat test is required after the issue is resolved.

In contrast, a negative result means no detectable analyte was found and the test ran under valid conditions; a positive result means the analyte was detected; and an inconclusive result indicates ambiguity in the outcome even though the run completed, but not necessarily due to a clear instrument or procedure failure.