What is Measurement of Uncertainty?

Home - uncertainty

What is Measurement of Uncertainty?

Measurement Uncertainty (MU) relates to the margin of doubt that exists for the result of any measurement, as well as how significant the doubt is. For example, a piece of string may measure 20 cm plus or minus 1 cm, at the 95% confidence level. As a result, this could be written: 20 cm ±1 cm, with a confidence of 95%. Therefore, we are 95% sure that the piece of string is between 19 cm and 21 cm long.

Standards such as ISO 15189 require that the laboratory must determine uncertainty for each test. However, they have not specified how this should be done.

How do we calculate Measurement Uncertainty using QC data?

Employing your QC data to calculate uncertainty makes several assumptions; your test system is under control, the patient samples are treated in the same manner as your controls and gross outliers have been removed. If you choose to use your QC data to calculate this you should ensure that you use a commutable control with a matrix similar to that of a patient sample, with analytes present at clinically relevant levels

To calculate MU, labs must look at the intra-assay precision and inter-assay precision of their test.

Intra-assay precision: Sometimes known as ‘within run’ precision, is where 20 or more replicates of the same sample are run at the same time, under the same conditions (calculated from a single experiment). Intra-assay precision helps to assess systematic uncertainties

Inter-assay precision: Sometimes known as ‘between run’ precision, is where 20 or more replicates are run at different times – e.g. 1 replicate every day for 20 days (can be calculated from routine IQC data). Inter-assay precision can help identify random uncertainties within the test system.

*The Australian Association of Clinical Biochemists (AACB) recommends that at least 6 months’ worth of QC data are used when calculating the inter-assay precision1.

Once the data is collected, you must calculate the standard error of the mean (SEM) of the intra-assay precision (A) and the SD of the inter-assay precision (B) in order to measure the uncertainty (u). Once A and B have been calculated, they need to be squared, added together and the square root of the sum found:

As uncertainty is calculated as SD and 1SD is equal to 68% confidence on a standard Gaussian curve, we can conclude that if we multiply using a coverage factor of 2, we can attain 2SD confidence of 95%. This is known as the Expanded Uncertainty (U):

What is the Advantage of Measurement Uncertainty for a lab?

Labs need to carry out MU as it is a requirement of ISO 15189. It states: “The laboratory shall determine measurement uncertainty for each measurement procedure, in the examination phases used to report measured quantity values on patients’ samples. The laboratory shall define the performance requirements for the measurement uncertainty of each measurement procedure and regularly review estimates of measurement uncertainty”.

MU also helps determine whether the difference between two results is negligible due to uncertainty or significant due to a genuine change in condition of the patient; giving labs a greater confidence in reported results.

How can Randox help?

Our new Acusera 24.7 Live Online software provides automatic calculation of MU, saving valuable time and helping labs meet ISO 15189 requirements with ease.

Contact marketing@randox.com to find out how your lab can benefit from Acusera 24.7 Live Online


Request a meeting
×
Make an Enquiry - RX series
×
Make an Enquiry - Reagents
×
Kit Insert Request - Reagents
  • Signing up to our mailing list is quick and easy. We do not wish to send you any spam or junk email, therefore, you can expect to receive mailshots including new product launches and updates, market trends, attendance at key industry events and much more. Randox Laboratories promise never to sell your data and we will keep all your details, safe and secure. Read more in our Privacy Policy.
×
Kit Insert Request - Reagents
  • Signing up to our mailing list is quick and easy. We do not wish to send you any spam or junk email, therefore, you can expect to receive mailshots including new product launches and updates, market trends, attendance at key industry events and much more. Randox Laboratories promise never to sell your data and we will keep all your details, safe and secure. Read more in our Privacy Policy.
×
Make an Enquiry - Reagents
×
Make an Enquiry - Quality Control
×
Make an Enquiry - RIQAS
×
Make an Enquiry - RIQAS
×
Make an Enquiry - Quality Control
×
Make an Enquiry
  • Signing up to our mailing list is quick and easy. We do not wish to send you any spam or junk email, therefore, you can expect to receive mailshots including new product launches and updates, market trends, attendance at key industry events and much more. Randox Laboratories promise never to sell your data and we will keep all your details, safe and secure. Read more in our Privacy Policy.
×
Make an Enquiry - Biochip
  • This field is for validation purposes and should be left unchanged.
×
Make an Enquiry - Molecular
  • Signing up to our mailing list is quick and easy. We do not wish to send you any spam or junk email, therefore, you can expect to receive mailshots including new product launches and updates, market trends, attendance at key industry events and much more. Randox Laboratories promise never to sell your data and we will keep all your details, safe and secure. Read more in our Privacy Policy.
  • This field is for validation purposes and should be left unchanged.
×
Make an Enquiry - Future Diagnostics
×
Make an Enquiry - RX series (Product)
×
Make an Enquiry - Quality Control
  • Signing up to our mailing list is quick and easy. We do not wish to send you any spam or junk email, therefore, you can expect to receive mailshots including new product launches and updates, market trends, attendance at key industry events and much more. Randox Laboratories promise never to sell your data and we will keep all your details, safe and secure. Read more in our Privacy Policy.
×
Make an Enquiry - RIQAS
  • Signing up to our mailing list is quick and easy. We do not wish to send you any spam or junk email, therefore, you can expect to receive mailshots including new product launches and updates, market trends, attendance at key industry events and much more. Randox Laboratories promise never to sell your data and we will keep all your details, safe and secure. Read more in our Privacy Policy.
×
Make an Enquiry - Reagents
  • Signing up to our mailing list is quick and easy. We do not wish to send you any spam or junk email, therefore, you can expect to receive mailshots including new product launches and updates, market trends, attendance at key industry events and much more. Randox Laboratories promise never to sell your data and we will keep all your details, safe and secure. Read more in our Privacy Policy.
×
Por favor, introduzca sus datos para ver nuestro último seminario
×
Wyślij zapytanie
  • Rejestracja na naszej liście mailowej jest szybka i łatwa. Nie chcemy wysyłać e-maili zawierających spam lub wiadomości, które są automatycznie przekierowywane do kosza. W zawiązku z czym firma Randox deklaruje, że będzie wysyłac tylko informacje na temat nowych produktów,akutalizacji obecnych, trendów rynkowych, wydarzeń branżowych itp. Firma Randox Laboraotries obiecuje, że Państwa dane nie będą nigdzie przekazane, a przechowywanie owych danych będzie się odbywało z zachowaniem największego bezpieczeństwa. Prosimy o przeczytani naszje Polityki Prywatności.
×
Wyślij zapytanie
  • Rejestracja na naszej liście mailowej jest szybka i łatwa. Nie chcemy wysyłać e-maili zawierających spam lub wiadomości, które są automatycznie przekierowywane do kosza. W zawiązku z czym firma Randox deklaruje, że będzie wysyłac tylko informacje na temat nowych produktów,akutalizacji obecnych, trendów rynkowych, wydarzeń branżowych itp. Firma Randox Laboraotries obiecuje, że Państwa dane nie będą nigdzie przekazane, a przechowywanie owych danych będzie się odbywało z zachowaniem największego bezpieczeństwa. Prosimy o przeczytani naszje polityki prywatności.
×
Wyślij zapytanie
  • Rejestracja na naszej liście mailowej jest szybka i łatwa. Nie chcemy wysyłać e-maili zawierających spam lub wiadomości, które są automatycznie przekierowywane do kosza. W zawiązku z czym firma Randox deklaruje, że będzie wysyłac tylko informacje na temat nowych produktów,akutalizacji obecnych, trendów rynkowych, wydarzeń branżowych itp. Firma Randox Laboraotries obiecuje, że Państwa dane nie będą nigdzie przekazane, a przechowywanie owych danych będzie się odbywało z zachowaniem największego bezpieczeństwa. Prosimy o przeczytani naszje polityki prywatności.
×
Wyślij zapytanie
    Rejestracja na naszej liście mailowej jest szybka i łatwa. Nie chcemy wysyłać e-maili zawierających spam lub wiadomości, które są automatycznie przekierowywane do kosza. W zawiązku z czym firma Randox deklaruje, że będzie wysyłac tylko informacje na temat nowych produktów,akutalizacji obecnych, trendów rynkowych, wydarzeń branżowych itp. Firma Randox Laboraotries obiecuje, że Państwa dane nie będą nigdzie przekazane, a przechowywanie owych danych będzie się odbywało z zachowaniem największego bezpieczeństwa. Prosimy o przeczytani naszje polityki prywatności .
×
귀하의 문의 사항 제출
    Signing up to our mailing list is quick and easy. We do not wish to send you any spam or junk email, therefore, you can expect to receive mailshots including new product launches and updates, market trends, attendance at key industry events and much more. Randox Laboratories promise never to sell your data and we will keep all your details, safe and secure. Read more in our Privacy Policy.
×
귀하의 문의 사항 제출
×
귀하의 문의 사항 제출
×
귀하의 문의 사항 제출
×
Downloads
×
Contact

<p>

    Randox Clinical Chemistry Products Join the Randox Laboratories Mailing List * I would like to receive emails with new product releases and updates from Randox Laboratories, market trends, and more. I do not want to receive email marketing from Randox. Signing up to our mailing list is quick and easy. We do not want to send you any spam or junk emails, therefore, you can expect to receive mailshots including new product launches and updates, market trends, attendance at key industry events and much more. Randox Laboratories promises never to sell your data and we will keep all your details, safe and secure. Read more in our Privacy Policy.
</p>

×
Enquire Now - Coronavirus Testing
  • Signing up to our mailing list is quick and easy. We do not wish to send you any spam or junk email, therefore, you can expect to receive mailshots including new product launches and updates, market trends, attendance at key industry events and much more. Randox Laboratories promise never to sell your data and we will keep all your details safe and secure. Read more in our Privacy Policy.
×