Evaluation of Biochemistry Tests with Six Sigma

Abstract

Background: Six sigma is a quality indicator used in biochemistry laboratories to evaluate analytical performance. We aimed to evaluate our analytical performance by calculating the six sigma values of some tests in our own laboratory.
Materials and Methods: In this study, we used the five-month internal quality control values of 49 biochemistry and immunoassay tests analyzed on Beckman Coulter AU 5800 and DXI 800 analyzers. We calculated six sigma data using 2 different allowed total error values (% TEa)[(Clinical Laboratory Improvement Amendments (CLIA) and Ricos biyological variation]. We accepted three and above six sigma values as an indicator of good performance.
Results: When we evaluated according to CLIA criteria, the analytical performance of ALP, CK and amylase was 6 and above, while according to Ricos, only the analytical performance of the prolactin test was 6 and above at both control levels.
Conclusions: Six sigma is important in quality control evaluation. When performing the sigma calculation, it should be kept in mind that the permissible total error values used may cause different performance data.

Keywords

• Six sigma
• Sigma metrics
• Total quality management

Altı Sigma ile Biyokimya Testlerinin Değerlendirilmesi

Abstract

Amaç: Altı sigma, biyokimya laboratuvarlarında analitik performansın değerlendirmesi için kullanılan bir kalite indikatörüdür. Biz de kendi laboratuvarımızda bazı testlerin altı sigma değerlerini hesaplayarak analitik performansımızı değerlendirmeyi amaçladık.
Materyal ve Metod: Bu çalışmada, Beckman Coulter AU 5800 ve DXI 800 analizörlerinde çalıştığımız 49 biyokimya ve immunassay testinin beş aylık internal kalite kontrol değerlerini kullandık. 2 farklı izin verilen toplam hata değerleri (%TEa) [(Clinical Laboratory Improvement Amendments (CLIA), Ricos biyolojik varyasyon] ile altı sigma verilerini hesapladık. Üç ve üzeri altı sigma değerlerini iyi performans göstergesi olarak kabul ettik.
Bulgular: CLIA kriterlerine göre değerlendirme yaptığımız zaman ALP, CK ve amilazın analitik performansı 6 ve üzeri iken, Ricos’a göre sadece prolaktin testinin her iki kontrol düzeyinde analitik performansı 6 ve üzeri idi.
Sonuç: Altı sigma, kalite kontrol değerlendirmede önemlidir. Sigma hesabı yapılırken kullanılan izin verilen total hata değerlerinin farklı performans verilerine neden olabileceği akılda tutulmalıdır.

Keywords

• Altı Sigma
• Sigma ölçümleri
• Yüzde Bias
• Toplam analitik hata

References

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