The PT Interval Exceptions tab helps identify PT results where there is less than 7 days between the close of one study to the opening of the next. From 5.2.1.2 of the TNI standard:

• The opening date of PT study samples for a particular field of accreditation must be at least seven (7) calendar days after the closing date of a PT study for the same field of accreditation.
• A laboratory that analyzes and reports PT study results with an opening date of subsequent PT studies for the same field of accreditation that are closer than seven (7) days from the closing date of the previous PT study are invalid for the purposes of compliance with this Standard and are not counted toward the laboratory’s PT history of the most recent three (3) attempts.

AB Manager’s PT Summary table indicates, for a specific matrix, analyte, and technology (see Note 1), the most recent 3 PT Studies (with corresponding dates, evaluation, and methods used). Study 1 is the oldest and Study 3 is the most recent.

The PT Interval Exceptions table displays any PT data where the time between studies is less than 7 days, specifically:

• Close 1 to Open 2 is <7 days, or
• Close 2 to Open 3 is <7 days.

If PT interval exceptions are reviewed and determined to be invalid, the user may select those results, select update selected, and then change Active to No. Marking PT results as inactive will remove them from evaluation in the PT Summary. PT data marked as invalid can be reverted to valid in the Search PT Results table.

Note: To revert results back to Active, use the Search PT Results table to find and update the active status.

Note: AB Manager’s ‘PT Summary’ and ‘PT Interval Exceptions’ tabs group PT results by technology as per TNI 4.3.4. As a result, when multiple methods with the same technology are reported, there may be cases where a single method may have an acceptable PT internal but may fail as a technology group. These exceptions must be evaluated manually.