Record of Repeatabilities and Uncertainty

Description, Purpose and Objective

NOTE

The Repeatability Record view is the quality control module responsible for documenting and calibrating the short-term precision (repeatability) and calibration uncertainty of the analytical methods used by the organization.

The repeatability and uncertainty of a test includes:

• Repeatability (SD): The standard deviation obtained by repeatedly processing the same control sample in a very short period (intra-assay or same-day precision).
• Calibrator Uncertainty: The numerical value of the variability or margin of doubt inherent to the standard calibrator material provided by the reagent manufacturer.
• Effective Since: The effective date from which these values ​​are associated with the analytical calculations.

The objective of this view is to record the initial imprecision variables required to mathematically calculate the Combined Measurement Uncertainty and Expanded Uncertainty of the laboratory results, ensuring compliance with the international quality standard ISO 15189.

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Context of Use

This panel is configured by technical quality coordinators to:

• Enter data from method verifications: Record the deviation obtained in the initial repeatability studies (20 consecutive replicates) when installing a new analytical instrument.
• Record calibrator lot changes: Update the Calibrator Uncertainty value each time a new calibrator lot is entered from the manufacturer.
• Calculate Measurement Uncertainty: Provide the base data that the system will cross-reference with patient results to report uncertainty in the final laboratory reports.

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Possible Actions

1. Check Repeatabilities

Displays the list of active QC tests and their control lots, indicating: Assay, Instrument, Lot, Method, the current Repeatability (SD) value, the recorded Calibrator Uncertainty, and the Effective Date (effective from). The search engine filters in real time by analyte, analyzer or lot number.

2. Inline Edition of Repeatability and Uncertainty

To register or update values:

1. Check the checkbox (Checkbox) in the first column of the test record you want to configure.

2. The selected row will be transformed into editable form fields:

   • Repeatability (SD): Enter the standard deviation calculated on the precision analytical runs (e.g. 0.045).
   • Calibrator Uncertainty: Enter the uncertainty value certified on the manufacturer's calibrator insert data sheet (e.g. 0.12).
   • Effective From: Select the effective date for these securities using the calendar.

3. Click the general "Save" button in the upper right corner of the panel to store all modified records.

3. Consult Repeatability History

Click the "History" button (clock icon ↩️) in the test row to display a pop-up window detailing the recording of previous repeatability and uncertainty values, facilitating quality audits on the historical performance of the equipment.

4. Export Repeatability Data

Click the download button in the table header to download the list of configured repeatabilities and uncertainties in .CSV format.

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Clinical Metrology: Uncertainty Estimation according to ISO 15189

NOTE

• Combined Typical Uncertainty ($u_c$): It quadratically combines the laboratory imprecision ($u_{\text{prec}}$ or repeatability) and the uncertainty of the value assigned to the calibrator ($u_{\text{cal}}$): $$u_c = \sqrt{u_{\text{prec}}^2 + u_{\text{cal}}^2}$$
• Expanded Uncertainty ($U$): Expresses the interval where the true value of the measurement is found with a 95% confidence level (coverage factor $k = 2$): $$U = k \times u_c = 2 \times u_c$$
• Clinical Importance: Knowing $U$ allows the bacteriologist and the treating physician to discern whether a variation in a patient's sequential results reflects a true clinical evolution or whether it corresponds to the metrological variability inherent to the analytical system.

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Roles and Permissions Required

Access to this parameterization module is reserved for the roles of Quality Director, Laboratory Coordinator and System Administrator. Requires the following technical permissions:

• Display and Audit: repeatibilities_read (allows you to consult the list, filter parameters and audit the current configurations).
• Management and Writing: repeatibilities_create, repeatibilities_update and