Uncertainty of Measurement (UoM) Calculator for Pathology Labs

What is Uncertainty of Measurement?

Uncertainty of Measurement (UoM, or MU) quantifies the doubt around a reported quantitative result. ISO 15189:2022 requires clinical labs to estimate MU for measured quantities, review it periodically, and make it available on request. It is expressed as a standard or expanded uncertainty (usually at 95% confidence, k=2).

The top-down approach

Clinical labs typically use the practical top-down method: combine the long-term imprecision from internal quality control (u_Rw, the CV of your IQC over time) with the uncertainty of the bias estimate (u_bias, from EQA/peer data). The combined standard uncertainty is u_c = √(u_Rw² + u_bias²), and the expanded uncertainty U = k × u_c with k=2.

What QCnomics does for you

Uses your accumulated IQC data to derive imprecision per analyte and level automatically.
Incorporates bias from EQA / peer comparison where available.
Reports combined and expanded uncertainty (k=2) per analyte, ready for the ISO 15189 file.
Recalculates as more QC data accumulates, so UoM stays current.

Frequently asked questions

How do clinical labs calculate UoM?

Most use the top-down approach: combine internal QC imprecision (CV) with the uncertainty of bias, then expand with k=2 for ~95% confidence. QCnomics does this per analyte from your own QC data.

Is UoM mandatory for ISO 15189:2022?

Yes, for measured quantitative results labs must estimate measurement uncertainty, review it, and provide it to users on request.

Do I need a spreadsheet for UoM?

No. QCnomics derives UoM automatically from accumulated IQC and EQA data and keeps it updated.

Do this automatically in QCnomics

Clinical-grade internal quality control and ISO 15189:2022 compliance in one platform.

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