In the published article, Van Heerden M, George JA, Khoza S. The application of sigma metrics in the laboratory to assess quality control processes in South Africa. Afr J Lab Med. 2022;11(1):a1344.
The correction has now been made on page 2 in the Methods section, under Data collection and analysis, paragraph 4 and should read:
Sigma metrics were calculated for each analyte on two levels as follows:
Sigma metrics were calculated for each analyte on two levels as follows:
The authors apologise for this error. The correction does not change the study’s findings of significance or overall interpretation of the study’s results or the scientific conclusions of the article in any way.