Tools, Technologies and Training for Healthcare Laboratories

Sigma Metric Bibliography

In our recent scouring of the scientific literature, we found more than 200 papers, written by more than 400 authors, published in more than 90 scientific journals, that discuss the Sigma-metric approach or demonstrate its implementation. If you seeking more examples and discussion of Sigma-metrics, this is a great place to start.

An Analytical Sigma-metric Bibliography

Last updated 2/3/25
compiled by Sten Westgard, MS

Since 2001, when the analytical Sigma-metric was introduced by James O. Westgard, labs around the world have adopted the technique and published their results. Below follows a list of more than 200 papers - none of them authored by Westgard, Westgard or Bayat, the principal experts of the field. Included with each paper is some notation of any specialized information. For example, HbA1c standardization has made particular use of the Sigma-metric approach. Other papers have discussed the differences found in different TEa specifications, and the need to "standardize" or "harmonize" the goals for Sigma-metrics.

If you don't see a paper here that you know discusses Sigma-metrics, let us know so we can add it to the list!

  1. Melahat Gurbuz, Analytical Performance Evaluation of a Clinical Microbiology Laboratory Using Sigma Metrics, J Contemp Med 2025; 15(1): 14-18. Doi:10.16899/jcm.1525964
  2. Hussien Hamid, Mousa Al-Wafi, Mohamed H. Ahmida, Abdulla M. Elmansoury, Mohamed Najah. Beyond Total Error: An observational comparative study of sigma metrics in long-term arterial blood gas analyzer performance. January 10, 2025. Cureus 17(1): e77236. DOI 10.7759/cureus.77236
  3. Claudio Ilardo, Chehine Lamarti, Batricia Al Muhanna, Michel Bastelica, Nathalie Benaily. Sentinel testing, analytical sigma metrics, and a risk management approach as part of a simplified method verification/validation process. Scand J Clin Lab Invest. Published online 12/19/24. https://doi.org/10.1080/00365513.2024.2442512
  4. Yasemin Erdogan-Doventas, Esma Ozemir-Anayurt, Hatice Erdogan, Pelin Kulan, Macit Koldas, Performance Evaluation of a Coagulation Laboratory Using Sigma Metrics and Quality Goal Index, Clin Lab 2024;70:2254-2257. DOI: 10.7754/Clin.Lab.2024.240619.
  5. Saurabh Singh, Mainsha Singh, Devesh Sharma, Ijen Bhattacharya, Mamta Padhy, Surabhi Puri, Utkarsh Singh Tomar. Application of Six Sigma Metrics for assessing the quality management of biochemical analytes in the clinical laboratory. Asian Journal of Medical Sciences, December 2024, Volume 15, issue 12, 70-78.
  6. P R Dy, K B Damian, E Q Villanueva. Evaluation of the Hematology Analyzer Test Performance Using Six Sigma Metrics: A Cross Sectional Study. October 2024. American Journal of Clinical Pathology 162(Supplement_1):S73-S73. DOI: 1093/ajcp/aqae129.162 [hematology]
  7. Internal Quality Controls in the Medical Laboratory: A Narrative Review of the Basic Principles of an Appropriate Quality Control Plan. Gruber L, Hausch A, Mueller T Diagnostics (Basel), 14(19):2223, 05 Oct 2024 [Integration into other approaches]
  8. Asma Rasheed, Sadia Sharif, Lubna Humayun, Tahir Naeem et al. The Analytical Performance Evaluation of Routine Clinical Chemistry Parameters by Six Sigma Approach: An Effective Tool for Laboratory Quality Management. September 2024. Annals of King Edward Medical University Lahore Pakistan 30(3). DOI: 21649/akemu.v30i3.5654.
  9. Beyond the basics: Sigma scores in laboratory medicine with variable total allowable errors (TEa). Yadav D, Rathore M, Banerjee M, Tomo S, Sharma P. Clin Chim Acta. 2024 Sep 24;565:119971. doi: 10.1016/j.cca.2024.119971. Online ahead of print. PMID: 39326693
    [Debating TEa differences]
  10. Yun Huang 1 2 , Callie Loveday  2 , Anne Vincent  1  Potential use of Six Sigma metrics in the quality control review of hospital glucose meters. 2024 Aug 22;10(17):e36651. doi: 10.1016/j.heliyon.2024.e36651. eCollection 2024 Sep 15. PMID: 39263160 PMCID: PMC11387332 DOI: 10.1016/j.heliyon.2024.e36651 [POC]
  11. Kübra Nazmiye, Nahide Ekici Günay, Derya Koçer. Six Sigma and Analytical Process in Biochemistry Laboratory of Kayseri City Hospital. August 2024. Öztürk N. K. ve ark. Türk Klinik Biyokimya Derg 2024; 22(2): 72-82 https://doi.org/10.56615/tkbd.2024.09 DOI: 56615/tkbd.2024.09.
  12. An assessment of analytical performance using the six sigma scale in second-trimester maternal prenatal screening practices in China.    Zhang J, Chen X, Wu J, Feng P, Wang W, Zhong K, Yuan S, Du Y, Zhang C, He F     Pract Lab Med, 41:e00422, 23 Jul 2024 PMID: 39155970 | PMCID: PMC11327568 [prenatal screening]
  13. Lincy Raj C, Poornima RT, Malawadi BN. July 2024 Asian Journal of Medical Sciences Sigma metrics – a good quality control guide to assess analytical performance of a clinical chemistry laboratory. 15(7):45-50. DOI: 3126/ajms.v15i7.64838. [educational]
  14. Debojyoti Bhattacharjee, Bithika Ghosh,Arghya Ray Chaudhuri, Kheya Mukherjee et al. Sigma metrics application in clinical biochemistry: Practical requisite or unfeasible misadventure.. June 2024 Asian Journal of Medical Sciences 15(6):29-34. DOI: 3126/ajms.v15i6.63624. [educational]
  15. Elsa Wulandari, Tri Dyah Astuti, Wahid Syamsul Hadi. ANALISIS HASIL KONTROL KUALITAS PEMERIKSAAN HEMOGLOBIN DAN HEMATOKRIT. June 2024. Jurnal Medika 9(1):20-27. DOI: 53861/jmed.v9i1.461. [hematology]
  16. Six Sigma driven QC management in hepatitis C serology. Khelil MM. Ann Biol Clin (Paris). 2024 Jun 5;82(2):215-224. doi: 10.1684/abc.2024.1885. PMID: 38702909
    [QC Design] [Serology]
  17. Harish Rangareddy, N. Shashidhar, Prabhavathi Prabhavathi. Kanala. A Retrospective Study to Evaluate the Quality Assurance of Thyroid Profile In A Tertiary Care Clinical Biochemistry Laboratory. April 2024. Journal of Clinical and Biomedical Sciences 14(1):13-18. DOI: 10.58739/jcbs/v14i1.24.24. [THYROID testing]
  18. Sonny Feisal Rinaldi, Anisa Agustia Ibadurrahmah, Surya Ridwanna, Harianto Harianto Comparison of the sigma metrics using the total error allowable algorithm with variation of bias source. April 2024 INDONESIAN JOURNAL OF MEDICAL LABORATORY SCIENCE AND TECHNOLOGY 6(1):27-34. DOI:33086/ijmlst.v6i1.4930. [TEa differences][bias differences]
  19. Bibek Pun Magar, Amit Thapa, Shreeman Acharya, Suman Lamichhane. Application of Sigma Metrics for Evaluating Analytical Performance of HbA1C Testing on D10- HbA1C Analyzer. April 2024. Journal of Drug Delivery and Therapeutics 14(4):27-32. DOI:22270/jddt.v14i4.6424. [HbA1c testing]
  20. A Novel Approach for Routinely Assessing Laboratory Sigma Metrics for a Broad Range of Automated Assays. Johanna J Miller, Alistair J Gammie. February 2024, The Journal of Applied Laboratory Medicine 9(3) DOI: 1093/jalm/jfad125. [alternative approaches][OrthoQuidel Vitros]
  21. Daly, M. Rishniw, P. A. Graham, K. P. Freeman. Repeat patient testing-quality control compared to commercial quality control material for the Sysmex XT-2000iV hematology analyzer in a multi-site veterinary laboratory. Vet Clin Pathol. 2024;53(Suppl. 1):48–59S. DOI: 10.1111/vcp.13332  [veterinary medicine]
  22. Shilpa N. Chitlange (Kasat), Shamali A. Jungare, Suresh G. Ghangale. SIX SIGMA METRICS: INDICATOR OF QUALITY ASSURANCE FOR CLINICAL BIOCHEMSITRY[stet] January 2024 Int. J. Adv. Res. 12(01), 156-162 DOI: 21474/IJAR01/18105. [educational]
  23. Saswati Das, Monika Garg, Neera Sharma. Sigma Metrics Assessment as Quality Improvement Methodology in a Clinical Chemistry Laboratory. January 2024. Indian Journal of Medical Biochemistry 27(2):23-27. DOI: 5005/jp-journals-10054-0218.
  24. V. Sychik, D.V. Burtsev, G.I. Lugovskaya, A. V. Moshev. Sigma-metric analysis of immunochemical studies with the establishment of quality requirements for the analysis based on its current state-of-the-art. January 2024. Laboratornaya sluzhba 13(2):39. DOI: 10.17116/labs20241301139.
  25. Dereje Mengesha Berta, Mekonnen Grima, Mulugeta Melku Gobezie, Aregawi Yalew. Assessment of hematology laboratory performance in the total testing process using quality indicators and sigma metrics in the northwest of Ethiopia: A cross‐sectional study. January 2024. Health Science Reports 7(1):e1833. DOI: 1002/hsr2.1833.
  26. Kathleen Freeman, Stefanie Klenner-Gastreich, Jérémie Korchia. The importance of quality control validation and relationships with total error quality goals and bias in the interpretation of laboratory results. Vet Clin Pathol. 2024;00:1–10. DOI: 10.1111/vcp.13321. [veterinary laboratory]
  27. Hussien Hamid1*, Khaled Algadafi2, Haneen Ehweedy3, Enas Aldrisi3, Assessment of Pre-analytical and Analytical
    Performance Using Sigma Metrics and Quality Goal Index: A Case Study on Liver Profile Analysis at Benghazi Medical Center. Mod Med Lab J. 2023; 6(2): 29-38
    e-ISSN 2371-770X. https://modernmedlab.com/article-1-143-en.html accessed 12/3/24.

  28. Jayesh Warade. Evaluation of Quality Control Performance of Gem Premier 4000 Using Inbuilt Intelligent Quality Management on Sigma Scale. December 2023. Indian Journal of Medical Biochemistry 27(1):9-13. DOI: 5005/jp-journals-10054-0217. [Werfen]

  29. Sohini Sengupta, Douglas W. Chung, Ramdhir Kumar, Ashok Rattan. Sigma metrics as quality indicators in guiding and tracking laboratory process improvement. December 2023. International Journal of Research in Medical Sciences 12(1). DOI: 18203/2320-6012.ijrms20233837. [Abbott]
  30. The Evaluation of the Quality Performance of Biochemical Analytes in Clinical Biochemistry Laboratory Using Six Sigma Matrices. Panda CR, Kumari S, Mangaraj M, Nayak S. Cureus, 15(12):e51386, 31 Dec 2023 PMID: 38292960 | PMCID: PMC10826247
  31. Shreya goel, Amit Nisal,Ankita Raj. Analysis of hematology quality control using six sigma metrics. November 2023 Indian Journal of Pathology and Microbiology 67(2). DOI: 4103/ijpm.ijpm_352_23. [hematology]
  32. Min Li, Xiaojuan Li, Xiaohong Lu, Feng Xue. Sigma metric used to evaluate the performance of haematology analysers: choosing an internal reference analyser for the laboratory. November 2023. Hematology 28(1). DOI: 1080/16078454.2023.2277498. [hematology]
  33. Ranjeeta Gadde. Analysis of biochemical analytes using six sigma metrics with two analyzers at an Indian lab setting. November 2023. Bioinformation 19(11):1043-1050. DOI: 6026/973206300191043.
  34. Amani MT Gusti, Malik S. Almuqati, Saleh A. Alkhilafi, Badr Helal Almuafa et al. IMPROVING QUALITY AND EFFICIENCY PERFORMANCE OF ANALYTICAL TESTING PROCESS USING SIGMA METRICS IN EMERGENCY LABORATORY OF KING FAHD ARMED FORCES HOSPITAL, JEDDAH, SAUDI ARABIA. November 2023. Int. J. Adv. Res. 11(11), 583-606 DOI: 21474/IJAR01/17860. [QC Design]
  35. Jairaman J, Thomas AVV, Laboratory, Sunway Medical Centre Sdn. Bhd., Malaysia. Available at: https://www.sunwaymedical. com/lab/wp-content/uploads/sites/3/2017/10/SIGMA-METRIC-PERFORMANCE-OF-TWO-PORTABLE-BLOOD-GAS-ANALYZERS-IN-ICU-AGAINST-CORE-LABORATORY-ANALYZER-AT-SUNWAY-MEDICAL-CENTR.pdf. Accessed on: 30 September 2023.
  36. Dereje Mengesha Berta, Mulugeta Melku Gobezie, Tiruneh Adane, Bisrat Birke Teketelew et al. Analytical Performance Evaluation of Hematology Analyzer Using Various TEa Sources and Sigma Metrics. September 2023. Pathology and Laboratory Medicine International Volume 15:65-75. DOI: 2147/PLMI.S414693. [hematology][TEa differences]
  37. Comparación de la métrica Sigma calculada con tres métodos de estimación del sesgo en 33 magnitudes químicas y 26 de inmunoensayo. Ercan Ş. Adv Lab Med, 4(3):246-257, 28 Aug 2023 PMID: 38162415 | PMCID: PMC10756148
  38. Comparison of Sigma metrics computed by three bias estimation approaches for 33 chemistry and 26 immunoassay analytes. Ercan Ş. Adv Lab Med. 2023 Jul 4;4(3):236-245. doi: 10.1515/almed-2022-0095. eCollection 2023 Sep. PMID: 38162416. [Benchmarking]
  39. Tülay Çevlik, Goncagul Haklar. Six Sigma Evaluation Using Bias Calculated from Internal Quality Control and External Quality Assurance Data. June 2023. Journal of Medical Biochemistry 43(1). DOI: 5937/jomb0-43052.
  40. Sathish Raju Nilakantam, Kusuma K S, Prashant Akila, Namratha G Dayananda. Sigma-Metric Analysis to Evaluate Quality Management of Analytical Processes Using RCA and QGI in a Clinical Biochemistry Laboratory, South India. June 2023. International Journal of Health & Allied Sciences 11(3). DOI: 55691/2278-344X.1035.
  41. Swarna Latha Sujatha Rani. Application of Sigma Metrics for Quality Improvement in OGH Laboratory's Analytical Chemistry. June 2023. International Journal of Science and Research (IJSR) 12(6):2844-2845. DOI: 21275/SR23628115519.
  42. Bagnu DUNDAR, Hatıce Nur HALIPCI TOPSAKAL. Evaluation of The Analytical Performance of Tests Run via Six Sigma Metrics on Same Brand Devices AYNI MARKA CİHAZLARDA ÇALIŞILAN TESTLERİN SİX SİGMA METRİKLERİ İLE ANALİTİK PERFORMANSININ DEĞERLENDİRİLMESİ. June 2023. Turkish Journal of Clinics and Laboratory 14(2). DOI: 18663/tjcl.1279837.
  43. Qurat Ul Ain 1 , Muhammad Younas, Zujaja Hina Haroon 1 , Sobia Irum Kirmani  1 , Muhammad Usman Munir  1 , Muhammad Anwar  1  Fifth Generation Quality Control of Immunoassay Parameters by Six Sigma Value.  J Coll Physicians Surg Pak. 2023 Jun;33(6):679-683. PMID: 37300265 DOI: 29271/jcpsp.2023.06.679
  44. Application of a six sigma model to evaluate the analytical performance of cerebrospinal fluid biochemical analytes and the design of quality control strategies for these assays: A single-centre study. Liu Q, Hu M, Yang F, Li Y, Yang F. Clin Biochem. 2023 Apr;114:73-78. doi: 10.1016/j.clinbiochem.2023.02.005. Epub 2023 Feb 14. PMID: 36796711 [cerebrospinal testing] [QC Design]
  45. Anupapama Raj Karaattuthazhathu, PP Sathi, Lathi Nair, Mary Benny et al. Sigma Metrics as a Valuable Tool for Effective Analytical Performance and Quality Control Planning in Clinical Laboratory: A Retrospective Study. April 2023. National Journal of Laboratory Medicine 12(2). DOI: 7860/NJLM/2023/60440.2714.
  46. Ferina Yudita, Dwi Purbayanti, Fitria Hariati Ramdhani, Eka Jaya. Evaluasi Kontrol Kualitas Pemeriksaan Glukosa Darah di Laboratorium X Palangka Raya: Evaluation of Quality Control of Blood Glucose Examination in Laboratory X Palangka Raya. April 2023. Borneo Journal of Medical Laboratory Technology 5(2):358-365. DOI: 33084/bjmlt.v5i2.5184.
  47. Annie Ren, Xiao Yan Wang, Pow Lee Cheng, Vathany Kulasingam et al. Analytical Evaluation and Sigma Metrics of 6 Next Generation Chemistry Assays on the Abbott Architect System. March 2023. Clinica Chimica Acta 542(1):117276. DOI: 1016/j.cca.2023.117276. [Abbott]
  48. Development and clinical evaluation of an online automated quality control system for improving laboratory quality management. Shang X, Zhao F, Du J, Li R, Xia L, Hou L, Cheng X, Ding Y, Li P, Liu M, Ma C, Wang Z, Ding J, Ge Z, Wang G, Guo T, Fu Y, Xiao M, Yang Q, Qiu L, Xu Y. Clin Chim Acta. 2023 Feb 15;541:117240. doi: 10.1016/j.cca.2023.117240. Epub 2023 Feb 1. PMID: 36736683
  49. Evaluation of analytical performance of homocysteine LC-MS/MS assay and design of internal quality control strategy. Zhao F, Pan G, Hong M, Zhao H, Liu M, Wang S, Sun X, Cao Y. Clin Chem Lab Med. 2023 Jan 13;61(6):1069-1074. doi: 10.1515/cclm-2022-0805. Print 2023 May 25. PMID: 36635945 [QC Design] [Mass Spec]
  50. Neeraj Yadav, MukeshKumar Meena, Shailata Prisi, Ritu Singh et al.
    Six Sigma metrics as an indicator for Randox International Quality Assessment Scheme in clinical biochemistry laboratory: A pilot study with thyroid function test in a tertiary care hospital. January 2023. MAMC Journal of Medical Sciences 9(1):25. DOI: 4103/mamcjms.mamcjms_12_23. [international benchmarking] [thyroid testing]
  51. hao F, Pan G, Hong M, Zhao H, Liu M, Wang S, Sun X, Cao Y. Evaluation of analytical performance of homocysteine LC-MS/MS assay and design of internal quality control strategy. Z Clin Chem Lab Med. 2023 Jan 13;61(6):1069-1074. doi: 10.1515/cclm-2022-0805. Print 2023 May 25. PMID: 36635945 [QC Design] [Mass Spec]
  52. Jayakumari Shanthakumari, Srihita Mahavadi Effect of Matrix and Source of Quality Specification Data on the Sigma Metrics of Common Chemistry Analytes in Clinical Laboratory. January 2023. Indian Journal of Medical Biochemistry 26(1):1-8. DOI: 5005/jp-journals-10054-0201.
  53. Aleksandra Pašić, Emir Šeherčehajić. "Six SIGMA" standard as a level of quality of biochemical laboratories. December 2022. Sanamed 17(00):20-20 DOI: 5937/sanamed0-40408.
  54. Shirin Sulthana P.K., Raghavendra U., Shaheena Yassir, Mohammed Ansar et al. A comparative evaluation of six sigma metrics and quality goal index ratio 3 months prior to first lockdown due to COVID-19 pandemic and 3 months during lockdown in a NABL accredited central laboratory. November 2022. Biomedicine 42(5):1051-1057. DOI: 51248/.v42i5.2038.
  55. Oana Roxana Oprea, Elena-Cristina Preda, Ion Bogdan Mănescu, Minodora Dobreanu. Setting up an own laboratory performance-based internal quality control plan - a model for complete blood count. October 2022. Revista Romana de Medicina de Laborator 30(4):477-482. DOI: 2478/rrlm-2022-0036. [QC Design] [hematology]
  56. Eva Ayu Maharani, Rika Erviani, Rizana Fajruni'mah, Dewi Astuti. PENGGUNAAN SIX SIGMA SEBAGAI EVALUASI KONTROL KUALITAS PADA HEMATOLOGY ANALYZER SYSMEX XN-1000. October 2022. Jurnal Riset Kesehatan Poltekkes Depkes Bandung 14(2):263-269. DOI: 34011/juriskesbdg.v14i2.2106. [hematology]
  57. Labosud INOVIE, Claudio Ilardo. Application of SQC model to optimize an internal quality control schedule for Haemoglobin A1c measurement on the Capillarys analyzer. September 2022. International Journal of Medical Biochemistry 5(3). DOI: 14744/ijmb.2022.63496. [HbA1c] [Capillarys]
  58. Fengfeng Kang 1 , Weixing Li 1 , Yongyong Lou  2 , Zhiming Shan  1  Application of biological variation and sigma metrics to evaluate the performance of HbA1c in external quality assessment. Scand J Clin Lab Invest. 2022 Sep;82(5):398-403. doi: 10.1080/00365513.2022.2100822. Epub 2022 Jul 23. PMID: DOI: 10.1080/00365513.2022.2100822 [HbA1c]
  59. Anisha Mathew, Sanjukta Naik, Preeti Chauhan, Ekta Debnath. IJMSCR Assessment of analytical performance of Internal QC and External QC of HbA1c By 6 Sigma Using Total Allowable Error (TEa) calculated by CLIA 88, and NGSP. International Journal of Medical Science and Current Research | September-October 2022 | Vol 5 | Issue 5. [HbA1c][TEa differences]
  60. Song Z, Zhang J, Liu B, Wang H, Bi L, Xu Q. Practical application of European biological variation combined with Westgard Sigma Rules in internal quality control. Clin Chem Lab Med. 2022 Aug 29;60(11):1729-1735. doi: 10.1515/cclm-2022-0327. Print 2022 Oct 26. PMID: 36036501
  61. Amitkumar Virji Maheshwari, Kamlesh A. Sadariya, Hardik N Javia, Drdinesh Sharma. Quality improvement in clinical biochemistry laboratory using six sigma metrics and quality goal index. August 2022. Journal of Medical and Scientific Research, DOI: 17727/JMSR.2021/9-16.
  62. Devi Prasad Pradhan, Debasish Pandit, Sibasish Sahoo, Sucharita Mohanty. Six Sigma Metrics: An Evolving Indicator of Quality Assurance for Clinical Biochemistry. August 2022. Journal of Clinical and Diagnostic Research 16(8). DOI: 7860/JCDR/2022/56691.16718.
  63. Susan Daly, Peter A Graham, Kathleen P Freeman Quality control validation for a veterinary laboratory network of six Sysmex XT‐2000iV hematology analyzers. August 2022. Veterinary Clinical Pathology 51(9). DOI: 1111/vcp.13163
  64. Evaluation of Sigma Metrics and Westgard Rule Selection and Implementation of Internal Quality Control in Clinical Chemistry Reference Laboratory, Ethiopian Public Health Institute. Geto Z, Getahun T, Lejisa T, Tolcha Y, Bikila D, Bashea C, Meles M, Habtu W, Ashebir G, Negasa B, Sileshi M, Daniel Y, Gashu A, Challa F. Indian J Clin Biochem. 2022 Jul;37(3):285-293. doi: 10.1007/s12291-021-00994-x. Epub 2021 Aug 2. PMID: 35873618 [QC Design]
  65. Ainun Salsabella, Titin Aryani. Sigma Matrix of Ureum and Creatinine in Some Laboratories: Overview. July 2022. Medicra (Journal of Medical Laboratory Science/Technology) 5(1):40-46. DOI: 21070/medicra.v5i1.1628. [Creatinine testing]
  66. Bùi Thị Hồng Châu, Nguyễn Thị Băng Sương, Nguyễn Ngọc Bích Thảo, Nguyễn Thanh Trầm. ÁP DỤNG TỈ LỆ CHỈ SỐ MỤC TIÊU CHẤT LƯỢNG ĐỂ ĐÁNH GIÁ HỆ THỐNG QUẢN LÝ CHẤT LƯỢNG XÉT NGHIỆM HbA1c TRÊN MÁY TOSOH HPLC-723G11. July 2022. Tạp chí Y học Việt Nam 516(2). DOI: 51298/vmj.v516i2.3056. [HbA1ic][Tosoh]
  67. Marli Van Heerden, Jaya A George, Siyabonga Khoza. The application of sigma metrics in the laboratory to assess quality control processes in South Africa. June 2022. African Journal of Laboratory Medicine 11(1). DOI: 4102/ajlm.v11i1.1344.
  68. Swetha N K, Kusuma K S, Kabbathi Raghunathachar Sahana, Suma M Nataraj. Sigma metric analysis of quality indicators across the testing process as an effective tool for the evaluation of laboratory performance. June 2022. Medical Journal Armed Forces India 79(1). DOI: 1016/j.mjafi.2022.04.010.
  69. Pinki Mayankkumar Joshi, Urmi Kalrav Patel. Performance evaluation of routine analytes using six sigma principle in a stand-alone clinical laboratory. June 2022. International Journal of Clinical Biochemistry and Research 9(2):127-134. DOI: 18231/j.ijcbr.2022.026.
  70. Loris Wauthier, Laura Di Chiaro, Julien Favresse. Sigma Metrics in Laboratory Medicine: A Call for Harmonization. May 2022. Clinica Chimica Acta 532(2). DOI:1016/j.cca.2022.05.012. [harmonization]
  71. Hüseyin Yaman 1 , Hatice Bozkurt Yavuz 2 , Süleyman Caner Karahan  1 , Asım Örem  1 , Merve Katkat  1 , Sümeyye Aytekin Garip  1  Analytical performance evaluation of sensitive and old generation reagent in routine practical use: estradiol experience. Scand J Clin Lab Invest. 2022 Apr;82(2):150-155. doi: 10.1080/00365513.2022.2038259. Epub 2022 Feb 15. PMID: 35167775 DOI: 1080/00365513.2022.2038259
  72. Anisha Mathew, Ekta Debnath, Preeti Chauhan, Ritu Singh et al. Application of sigma metrics and method decision charts for assessment of quality assurance in BioRad D-10 HbA1c analyzer. International Journal of Medical Science and Current Research (IJMSCR) Volume 5, Issue 2, Page No: 465-469. March-April 2022. [HbA1c] [BioRad]
  73. Monica Gupta, Mustafa Ranapurwala, Khevna Kansara, Drmitul Navinchandra Chhatriwala. Application of sigma metrics in haematology laboratory. April 2022. International Journal of Clinical and Diagnostic Pathology 5(2):21-25. DOI: 33545/pathol.2022.v5.i2a.467. [hematology ]
  74. Loris Wauthier, Laura Di Chiaro, Julien Favresse. Application of Sigma metrics in laboratory medicine: comparison of 16 calculations. March 2022. Clinical Chemistry and Laboratory Medicine. DOI: 1515/cclm-2021-5026. [harmonization]
  75. Determination of Sigma metric based on various TEa sources for CBC parameters: the need for Sigma metrics harmonization. Seyda Ozdemir, Fatma Ucar. March 2022 Journal of Laboratory Medicine 46(2). DOI:1515/labmed-2021-0116. [TEa differences][harmonization]
  76. Şeniz Korkmaz. Sigma metric evaluation with different TEa targets in clinical biochemistry. March 2022. International Journal of Medical Biochemistry 5(2). DOI: 14744/ijmb.2022.81300. [TEa differences]
  77. Jeremie Korchia, Kathleen P Freeman. Total observed error, total allowable error, and QC rules for canine serum and urine cortisol achievable with the Immulite 2000 Xpi cortisol immunoassay. March 2022. Journal of veterinary diagnostic investigation: official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc 34(2):246-257. DOI: 1177/10406387221076129.
  78. Murat Keleş 1 Evaluation of the clinical chemistry tests analytical performance with Sigma Metric by using different quality specifications - Comparison of analyser actual performance with manufacturer data Biochem Med (Zagreb). 2022 Feb 15;32(1):010703. doi: 10.11613/BM.2022.010703. Epub 2021 Dec 15. PMID: 34955671 PMCID: PMC8672391 DOI: 11613/BM.2022.010703 [TEa differences]
  79. Moya-Salazar J, SantaMaria BM, Moya-Salazar MM, Rojas-Zumaran V, Chicoma-Flores K, Contreras-Pulache H. Six-sigma and quality planning of TORCH tests in the Peruvian population: a single-center cross-sectional study.  BMC Res Notes, 15(1):16, 11 Jan 2022. PMID: 35016699 | PMCID: PMC8753838 [TORCH testing]
  80. Mert Üğe, Mehmet Koseoglu, Serap Çuhadar et al Koagülasyon Testlerinde Altı Sigma Yöntemi ve Değerlendirilmesi SIX SIGMA MANAGEMENT AND EV[A]ULATION IN COAGULATION TESTS January 2022. DEU Tıp Derg 2022;36(1): 1. J DEU Med 2022;36(1): 1 doi: 10.5505/deutfd.2021.97769 [coagulation testing]
  81. Margit Gajjar, Jigar Parmar, Gaurav Modi, Dipti Gajjar. Application of Six Sigma tool as Quality Indicator for evaluation of analytical phase of sample processing. January 2022. International Journal of Health and Clinical Research, 2022; 5(3):613-617.
  82. Newton DW, Vandepoele N, Yundt-Pacheco JC, Gauthier D, Bachman MA. Management of Cytomegalovirus, Epstein-Barr Virus, and HIV Viral Load Quality Control Data Using Unity Real Time. J Clin Microbiol. 2022 Jan 19;60(1):e0167521. doi: 10.1128/JCM.01675-21. Epub 2021 Oct 20. PMID: 34669458 [CHECK THIS] [Viral load testing]
  83. Rogious Mbasani, Luo Xigang, Nelson Musilanga. Evaluation of clinical biochemical laboratory analytical process performance using sigma metrics and quality goal index. December 2021. Chinese Journal of Medical Research 4(4):71-78. DOI: 37515/cjmr.091X.4403.
  84. Roberto Carboni-Huerta, Klever Saenz. Sigma and Risk in the Quality Control Routine: Analysis in Chilean Clinical Laboratories. December 2021. The Journal of Applied Laboratory Medicine 7(2). DOI: 1093/jalm/jfab145.
  85. Randolph M Baral, Kathleen P Freeman, and Bente Flatland. Comparison of serum and plasma SDMA measured with point-of-care and reference laboratory analysers: implications for interpretation of SDMA in cats. Journal of Feline Medicine and SurgeryVolume 23, Issue 10, October 2021, Pages 906-920 https://doi.org/10.1177/1098612X20983260
  86. Application of a six sigma model to evaluate the analytical performance of urinary biochemical analytes and design a risk-based statistical quality control strategy for these assays: A multicenter study. Liu Q, Bian G, Chen X, Han J, Chen Y, Wang M, Yang F. J Clin Lab Anal. 2021 Nov;35(11):e24059. doi: 10.1002/jcla.24059. Epub 2021 Oct 15. PMID: 34652033 Fr [urinary testing] [QC Design] [Risk Management
    t]
  87. Yanfen Luo, Xingxing Yan, Qian Xiao, Songbang Ou et al. Application of Sigma metrics in the quality control strategies of immunology and protein analytes. October 2021. Journal of Clinical Laboratory Analysis 35(11):e24041. DOI: 1002/jcla.24041. [Immunology testing]
  88. Imola Györfi, Krisztina Pál, Ion Bogdan Mănescu, Minodora Dobreanu et al Atellica CH 930 chemistry analyzer versus Cobas 6000 c501 and Architect ci4100 - a multi-analyte method comparison. October 2021. Revista Romana de Medicina de Laborator 29(4):421-438. DOI: 2478/rrlm-2021-0027.
  89. Dilara Bal Topcu, Ahmet Ozsoy, Fatma Ucar, Yesim Oztas et al Analytical Process Evaluation of Biochemistry Laboratory by Using Six Sigma Method. September 2021 Acta Medica 52(3):1-6 DOI: 32552/2021.ActaMedica.563.
  90. Nareshni Moodley, Verena Gounden. Assessment of Sigma Metrics for Routine Chemistry Testing in 4 Laboratories in Kwa-Zulu Natal, South Africa. October 2021. The Journal of Applied Laboratory Medicine 7(3). DOI: 1093/jalm/jfab117.
  91. Internal Quality Control Data of Urine Reagent Strip Tests and Derivation of Control Rules Based on Sigma Metrics. Park H, Ko Y. Ann Lab Med. 2021 Sep 1;41(5):447-454. doi: 10.3343/alm.2021.41.5.447. PMID: 33824232 [urine testing][QC design]
  92. Özlem Gülbahar, Murat Kocabıyık, Mehmed Zahid Çıracı, Mine Taşlıpınar et al. Analytical Process Evaluation of Biochemistry Laboratory by Using Six Sigma Method. September 2021. Acta Medica 52(3):1-6. DOI: 32552/2021.ActaMedica.563
  93. Akash Mishra, Rakesh Pokhrel, Uttam Budhathoki, Mithileshwor Raut et al. Six-Sigma Methodology for Quality Monitoring in a Teaching Hospital Biochemistry Laboratory in Nepal. August 2021. Journal of Institute of Medicine Nepal 43(2):7-12. DOI: 59779/jiomnepal.1164.
  94. Reham Abo Elwafa, Wafaa Ahmed El‐Neanaey, Nihal Mahmoud AbdEllatif, Reham Abo Elwafa. Evaluation of Sigma metric approach for monitoring the performance of automated analyzers in hematology unit of Alexandria Main University Hospital. July 2021. International Journal of Laboratory Hematology 43(2). DOI: 1111/ijlh.13660.
  95. Sigma Metrics: A Valuable Tool for Evaluating the Performance of Internal Quality Control in Laboratory. Kashyap A, Sampath S, Tripathi P, Sen A. J Lab Physicians. 2021 Jun 28;13(4):328-331. doi: 10.1055/s-0041-1731145. eCollection 2021 Dec. PMID: 34975251 [Educational]
  96. Jean-Marc Giannoli 1 , Stéphanie Albarede 2 , Thierry Avellan  1 , Jean-Pierre Bouilloux  1 , Régine Cartier  3 , Richard Cohen  3 , Nathalie Colard  1 , Luc Essemilaire  1 , Jean-Louis Galinier  2 , Mathieu Kuentz  4 , Mickaël Paris  1 , Henri Portugal  1 , Florian Scherrer  1 , Jean-Pascal Siest  5 , Anne Vassault  6 , Jean-Michel Vialle  1  Recommendations for the application and follow-up of quality controls in medical laboratories Biochem Med (Zagreb). 2021 Jun 15;31(2):020501. doi: 10.11613/BM.2021.020501. Epub 2021 Apr 15. PMID: 33927549 PMCID: PMC8047787 DOI: 11613/BM.2021.020501 [national recommendation]
  97. Application of the sigma metrics to evaluate the analytical performance of cystatin C and design a quality control strategy. Liu Q, Zhu W, Bian G, Liang W, Zhao C, Yang F. Ann Clin Biochem. 2021 May;58(3):203-210. doi: 10.1177/0004563220988032. Epub 2021 Jan 18. PMID: 33393354 [QC Design] [Cystatin C]
  98. Application of a six sigma model to the evaluation of the analytical performance of serum enzyme assays and the design of a quality control strategy for these assays: A multicentre study. Liu Q, Chen X, Han J, Chen Y, Wang M, Zhao J, Liang W, Yang F. Clin Biochem. 2021 May;91:52-58. doi: 10.1016/j.clinbiochem.2021.02.004. Epub 2021 Feb 20. PMID: 33617847
  99. Lokesh kumar Sharma, Rashmi Datta, Neera Sharma Sigma Metric Evaluation of Drugs in a Clinical Laboratory: Importance of Choosing Appropriate Total Allowable Error and a Troubleshooting Roadmap. May 2021. Journal of Laboratory Physicians 13(05). DOI: 1055/s-0041-1726572. [TDM testing][TEa differences]
  100. Fatima Kanani, Adnan Haider Kazmi, Bushra Kaleem. Sigma metrics of Alinity ci system – a study on thirty-nine clinical chemistry and immunoassay parameters. April 2021. Advances in Laboratory Medicine / Avances en Medicina de Laboratorio 2(2):20210001. DOI: 1515/almed-2021-0001.
    [Abbott]
  101. Huub H. van Rossum, Andreas Bietenbeck, Mark Cervinski, Tony Badrick et al. Benefits, limitations, and controversies on patient-based real-time quality control (PBRTQC) and the evidence behind the practice. March 2021. Clinical Chemistry and Laboratory Medicine 59(7) DOI: 1515/cclm-2021-0072. [alternative approaches]
  102. Sang-wook Kim, Yunjung Cho, Seung Gyu Yun. Evaluating the Performance of an Automated Chemistry Analyzer Using Sigma Metrics. January 2021. Laboratory Medicine Online 11(1):11-16. DOI: 47429/lmo.2021.11.1.11
  103. Muzaffer KATAR, Köksal DEVECİ, Zeliha Cansel Ozmen. Evaluation of The Total Quality Performance of Our Clinical Laboratory With Six-Sigma Method. January 2021. Journal of Contemporary Medicine 11(1):34-40. DOI: 16899/jcm.770304.
  104. Parul Goel, Gagandeep Malik, Suvarna Prasad, Kapil Goel. Analysis of performance of clinical biochemistry laboratory using Sigma metrics and Quality Goal Index. January 2021. Practical Laboratory Medicine 23(7):1-6. DOI: 1016/j.plabm.2020.e00195.
  105. K P Mekhala. A retrospective study to evaluate the performance of internal quality control in a biochemistry laboratory using sigma metrics. January 2021. International Journal of Clinical Biochemistry and Research 7(4):426-429. DOI: 18231/j.ijcbr.2020.090.
  106. Mulugeta Teshome, Abebaw Worede, Daniel Asmelash. Total Clinical Chemistry Laboratory Errors and Evaluation of the Analytical Quality Control Using Sigma Metric for Routine Clinical Chemistry Tests. January 2021. Journal of Multidisciplinary Healthcare DOI: 10.2147/JMDH.S286679.
  107. Başak Oktay. Assessment of analytical process performance by using six sigma method: comparison of two biochemistry analyzers. Int J Med Biochem 2021;4(2):97-103  January 2021. DOI: 14744/ijmb.2021.14633.
  108. Anderson Ramos Carvalho, Osmar Luiz Magalhães de Oliveira. Métrica Seis Sigma em análises clínicas e a qualidade na rotina laboratorial. January 2021. Revista Brasileira de Análises Clínicas 53(4). DOI: 21877/2448-3877.202102175.
  109. Yasemin Erdoğan Döventas. The Tools For Evaluating The Performance In Hba1c Analyzer: Sigma Metric And Quality Goal Index Ratio. January 2021. International Journal of Medical Biochemistry 5(1). DOI: 14744/ijmb.2021.77598. [HbA1c]
  110. Çiğdem Yücel, Müjgan Ercan, Murat Kizilgun. The evaluation of analytical performance of Total PSA and Free PSA tests by using 6-sigma method. January 2021. Turkish Bulletin of Hygiene and Experimental Biology 78(2):153-158. DOI: 5505/TurkHijyen.2020.19052. [PSA testing]
  111. Koshy JS, Raza A. Sigma metrics in quality control-an innovative tool.   https://www.ijcbr.in/article-download/full-text/15612 Int J Clin Biochem Res. 2021;8:253–259. [educational]
  112. Tuğba Öncel Van, Mehmet Koseoglu, Hayat Özkanay, Figen Narin. Fertilite Fonksiyon Testlerinin Sigmametrik Yöntem ile Analitik Kalitesinin Değerlendirmesi. Türk Klinik Biyokimya Derg 2021; 19(1): 56-62
  113. Xia Y, Li M, Li B, Xue H, Lin Y, Li J, Ji L. Sigma metrics application for validated and non-validated detecting systems performance assessment. J Clin Lab Anal, 35(3):e23676, 13 Dec 2020. PMID: 33314338 | PMCID: PMC7957966
  114. Smita Vasava, Roshni G. Sadaria. Application of Sigma Metrics for Evaluating the Analytical Performance of Thyroid Profile and Cortisol in Clinical Biochemistry Laboratory. December 2020. Journal of Clinical and Diagnostic Research 14(12). DOI: 7860/JCDR/2020/47345.14391. [thyroid testing]
  115. SongQing Peng, JinFei Zhang, WuQiong Zhou, Zhong Han et al. Practical application of Westgard Sigma rules with run size in analytical biochemistry processes in clinical settings. December 2020. Journal of Clinical Laboratory Analysis 35(3). DOI: 1002/jcla.23665. [QC Frequency] [Westgard Sigma Rules]
  116. Yasemin Üstündağ, kağan Huysal, Cuneyt Eris, Senol Yavuz et al. Evaluation of Sigma value and quality goal index for brain natriuretic peptide test. Int J Med Biochem 2020;3(3):178-82 October 2020. DOI: 14744/ijmb.2020.74046. [brain natriuretic peptide testing]
  117. Eline van der Hagen, Sanne Leppink, Karin Bokkers. Cas Weykamp et al. Evaluation of the ARKRAY HA-8190V instrument for HbA1c. December 2020. Clinical Chemistry and Laboratory Medicine DOI: 1515/cclm-2020-1300.
  118. Liu Y, Cao Y, Liu X, Wu L, Cai W.  Evaluation of the analytical performance of endocrine analytes using sigma metrics. J Clin Lab Anal, 35(1):e23581, 20 Sep 2020
    PMID: 32951270 | PMCID: PMC7843286
  119. Sholhui Park, Wookeun Lee, Tae-Dong Jeong, Ki-Sook Hong et al. Application of Six Sigma Metrics to Improve Quality Control for Point-of-care Glucose Testing. July 2020. The Ewha Medical Journal 43(3):43-48. DOI: 12771/emj.2020.43.3.43. [POC] [QC Design]
  120. Sanem Karadag Gecgel, Sevim Esmedere Eren. Use of six sigma metrics in assessing the performance of the ımmunonephometric device in C-reactive protein measurements. Al Ameen J Med Sci 2018 ; 11(2): 82 – 87. July 2020.
  121. Xia Y, Wang X, Yan C, Wu J, Xue H, Li M, Lin Y, Li J, Ji L. Risk assessment of the total testing process based on quality indicators with the Sigma metrics. Clin Chem Lab Med. 2020 Jul 28;58(8):1223-1231. doi: 10.1515/cclm-2019-1190. PMID: 32146438
  122. Myungsuk Ji. Six Sigma Analysis of Vitamin D Measurement Using External Quality Assessment Program. June 2020. Korean Journal of Clinical Laboratory Science 52(2):91-97. DOI: 15324/kjcls.2020.52.2.91.
  123. Claudio Ilardo, Cecile Reynaud, Regine Bonneton, Joel Barthes. Quality planning and control strategy for AQT90 flex Radiometer ® in point of care testing. June 2020. Scandinavian Journal of Clinical and Laboratory Investigation 80(1):1-6. DOI: 1080/00365513.2020.1768585. [Blood Gas][Radiometer]
  124. Meera S. Nithya K N. Sigma metrics - A guide to quality control strategy in clinical Biochemistry laboratory. June 2020. International Journal of Clinical Biochemistry and Research 7(2):267-271. DOI: 18231/j.ijcbr.2020.058.
  125. Dilek Iren Emekli, Kenan Guclu, Rukiye Nar, Esin Avci. Assessment of Analytical Performance of HbA1C Test by Six Sigma Methodology. J Basic Clin Health Sci 2020; 4:104-107. May 2020. DOI: 30621/jbachs.2020.869. [HbA1c testing]
  126. Şeniz Korkmaz. Analitik Evre Performansının Altı Sigma Metodu Kullanılarak Değerlendirilmesi. Türk Klinik Biyokimya Derg 2019; 17(3): 126-133.  April 2020.
  127. Athanasios Tzortzopoulos 1 2 , Vasilios Raftopoulos  3 , Michael A Talias  4  Performance characteristics of automated clinical chemistry analyzers using commercial assay reagents contributing to quality assurance and clinical decision in a hospital laboratory. Scand J Clin Lab Invest. 2020 Feb;80(1):46-54.  doi: 10.1080/00365513.2019.1695282. Epub 2019 Nov 26. PMID: 31766906 DOI: 1080/00365513.2019.1695282
  128. Petrova OV, Murygina OI, Shabanova GR, Nikulina DM. Quality assessment of biochemical studies using sigmametry. Laboratory Service. 2020;9(1):74‑77. (In Russ.) https://doi.org/10.17116/labs2020901174
  129. Moshkin AV. Classical Sigmametry in Laboratory Medicine. Laboratory Service. 2020;9(2):8‑10. https://doi.org/10.17116/labs202090218
  130. Pier Angeli Medina, Jenny Matibag, Sarah Jane Datay-Lim, Elizabeth Arcellana-Nuqui. A Pilot Study on the Evaluation of Clinical Chemistry Laboratory Test Performance using Six Sigma Metrics. December 2019. Philippine Journal of Pathology 4(2):31-36. DOI: 21141/PJP.2019.13.
  131. Wang H, Ma Y, Shan X. Evaluating the analytical quality control of urinary albumin measurements using sigma metrics. Clin Biochem. 2019 Nov;73:109-111. doi: 10.1016/j.clinbiochem.2019.07.011. Epub 2019 Jul 25. PMID: 31351987 [QC Design] [Benchmarking][urine testing]
  132. Fumeng Yang, Wenjun Wang, Qian Liu, Wei Liang et al. ANNALS EXPRESS: The application of six sigma to perform quality analyses of plasma proteins. November 2019. Annals of Clinical Biochemistry 57(2):00045632198920. DOI: 1177/0004563219892023. [protein testing]
  133. Athanasios Tzortzopoulos, Vasilios Raftopoulos, Michael A Talias. Performance characteristics of automated clinical chemistry analyzers using commercial assay reagents contributing to quality assurance and clinical decision in a hospital laboratory. November 2019. Scandinavian Journal of Clinical and Laboratory Investigation 80(2):1-9. DOI: 1080/00365513.2019.1695282.
  134. Tommaso Fasano, Jose Luis Bedini, Pierre-Antoine Fle, Katell Peoc'h et al. Multi-site performance evaluation and Sigma metrics of 20 assays on the Atellica chemistry and immunoassay analyzers. October 2019. Clinical Chemistry and Laboratory Medicine 58(1). DOI: 1515/cclm-2019-0699. [Atellica]
  135. Li R, Wang T, Gong L, Peng P, Yang S, Zhao H, Xiong P. Comparative analysis of calculating sigma metrics by a trueness verification proficiency testing-based approach and an internal quality control data inter-laboratory comparison-based approach.  J Clin Lab Anal, 33(9):e22989, 06 Aug 2019 [QC Design] [alternative calculations]
  136. Xia Wang, Dongmei Wen, Weijia Wang, Ting Hu et al. Application of biological variation and six sigma models to evaluate analytical quality of six HbA1c analyzers and design quality control strategy. August 2019. Artificial Cells, Nanomedicine, and Biotechnology 47(1):3598-3602. DOI: 1080/21691401.2019.1642207. [HbA1c]
  137. Li Runqing, Tengjiao Wang, Lijun Gong, Pan Xiong et al. Comparative analysis of calculating sigma metrics by a trueness verification proficiency testing‐based approach and an internal quality control data inter‐laboratory comparison‐based approach. August 2019. Journal of Clinical Laboratory Analysis 33(9). DOI: 1002/jcla.22989. [alternative calculations]
  138. Salma Sayeed, Suresh Babu Ganji, Ramadevi Mopuri. A SHORT-TERM ASSESSMENT OF ROUTINE CHEMISTRY PARAMETERS BY SIGMA METRICS AND QUALITY GOAL INDEX RATIO IN A TERTIARY CARE HOSPITAL LABORATORY. July 2019. Journal of Evolution of Medical and Dental Sciences 8(29):2303-2306. DOI: 14260/jemds/2019/505.
  139. Determination of sigma score based on biological variation for haemostasis assays: Fit-for-purpose for daily practice? J. Van Essen-Hollestelle, Janneke Ruinemans-Koerts, René N Idema, Moniek de Maat et al. June 2019. Clinica Chimica Acta 493:S525-S526. DOI:10.1016/j.cca.2019.03.1106. [hemostasis testing]
  140. Robiul Fuadi. USING SIX SIGMA TO EVALUATE ANALYTICAL PERFORMANCE OF HEMATOLOGY ANALYZER. April 2019. INDONESIAN JOURNAL OF CLINICAL PATHOLOGY AND MEDICAL LABORATORY 25(2):165. DOI: 24293/ijcpml.v25i2.1375.
  141. Babu Rao, Suresh Babu Ganji, Dawood Sulemani. TARGET SCORE OF RIQAS AND SIGMA METRICS FOR EVALUATING THE ANALYTICAL PERFORMANCE OF THYROID FUNCTION TESTING ON ADVIA CENTAUR XPT IMMUNOASSAY ANALYSER. February 2019. Journal of Evolution of Medical and Dental Sciences 8(7):447-50. DOI: 14260/jemds/2019/98 . [Thyroid testing]
  142. Yuping Zeng, He He, Ken Qin, Huang Henjian et al. Practical application of the sigma-metric run size nomogram for multistage bracketed statistical quality control analysis of eight enzymes. February 2019. Clinica Chimica Acta 492(Pt 1). DOI: 1016/j.cca.2019.02.006. [QC Frequency]
  143. Suneetha Revupalli, Suresh Babu Ganji. Evaluation of Quality Assurance in a New Clinical Chemistry Laboratory by Six Sigma Metrics. March 2019. Journal of Clinical and Diagnostic Research 13(3):BC04-07. DOI: 7860/JCDR/2019/40658.12666.
  144. Ganji SB, Revupalli S. Evaluation of quality assurance in a new clinical chemistry laboratory by Six Sigma metrics. https://jcdr.net/article_fulltext.asp?issn=0973-709x&year=2019&volume=13&issue=3&page=BC04&issn=0973-709x&id=12666 J Clin Diagn Res. 2019;13 [educational]
  145. Aggarwal K, Patra S, Acharya V, Agrawal M, Mahapatra SK. Application of six sigma metrics and method decision charts in improvising clinical Chemistry laboratory performance enhancement. Int J Adv Med. 2019;6(5):1524-30. doi:10.18203/2349-3933.ijam20194155.
  146. Jill E. Arnold, Melinda S. Camus, Kathy P. Freeman, Luca Giori, Emma H. Hooijberg, Unity Jeffery, Jérémie Korchia, Mandy J. Meindel, A Russell Moore, Sandra C. Sisson, Linda M. Vap, Jennifer R. Cook ASVCP Guidelines: Principles of Quality Assurance and Standards for Veterinary Clinical Pathology (version 3.0) Developed by the American Society for Veterinary Clinical Pathology's (ASVCP) Quality Assurance and Laboratory Standards (QALS) Committee. Vet Clin Pathol. 2019;48:542–618.
  147. Huang Y, Zhang T, Zhao H, Wang W, Zhang C, He F, Zhong K, Yuan S, Du Y, Wang Z. Performance evaluation of HbA1c measurement systems with sigma metric for 1066 laboratories in China. Clin Chim Acta. 2018 Dec;487:281-286. doi: 10.1016/j.cca.2018.10.015. Epub 2018 Oct 9. PMID: 30312599 [national benchmarking]
  148. Vijatha Thomas, P B Desai, Arun Mithrason. Evaluation of clinical biochemistry laboratory performance using sigma metrics. December 2018. International Journal of Clinical Biochemistry and Research 5(4):604-607. DOI: 18231/2394-6377.2018.0128.
  149. Monica Verma, Kiran Dahiya, Veena Singh Ghalaut, Vasudha Dhupper. Assessment of quality control system by sigma metrics and quality goal index ratio: A roadmap towards preparation for NABL. November 2018. World Journal of Methodology 8(3):44-50. DOI: 5662/wjm.v8.i3.44.
  150. Qian Liu, Mei Fu, Fumeng Yang, Changxin Zhao et al. Application of Six Sigma for evaluating the analytical quality of tumor marker assays. October 2018. Journal of Clinical Laboratory Analysis 33(2). DOI: 1002/jcla.22682.
  151. Jennifer Taher, Jake Cosme, Brian A. Renley, Paul M. Yip et al. A novel Sigma metric encompasses global multi-site performance of 18 assays on the Abbott Alinity system. October 2018. Clinical Biochemistry DOI: 10.1016/j.clinbiochem.2018.10.003.
  152. Carolyn A Sink, , . Evaluation of an in-clinic dry chemistry analyzer for canine, equine, and feline plasma samples, J Vet Diagn Invest 018 Oct 20;30(6):902–910. doi: 10.1177/1040638718809407 PMCID: PMC6505834  PMID: 30343645
  153. Lourdes C Vanyo, Kathleen P Freeman, Antonio Meléndez-Lazo, Mariana Teles, Rafaela Cuenca, Josep Pastor.  Comparison of traditional statistical quality control using commercially available control materials and two patient-based quality control procedures for the ADVIA 120 Hematology System Vet Clin Pathol. 2018 Sep;47(3):368-376.  PMID: 30168859, DOI: 10.1111/vcp.12645
  154. Fatma Ceyla Eraldemir. Evaluation of analytical quality of cardiac biomarkers in the emergency laboratory by sigma metrics. September 2018. Journal of Clinical and Analytical Medicine 10(1):35-40. DOI: 4328/JCAM.6003.
    [cardiac biomarkers]
  155. Muhammad Shariq Shaikh 1 , Sidra Asad Ali 2 , Anila Rashid  1 , Farheen Karim  1 , Bushra Moiz  1  Performance evaluation of a coagulation laboratory using Sigma metrics Int J Health Care Qual Assur. 2018 Jul 9;31(6):600-608. doi: 10.1108/IJHCQA-07-2017-0134. PMID: 29954266 DOI: 1108/IJHCQA-07-2017-0134 [coagulation testing]
  156. Giray Bozkaya, Nuriye Uzuncan, Sibel Bilgili, Ozlem Demirezen. Evaluation of Analytical Performance of Variant II Turbo HbA1c Analyzer According to Sigma Metrics. June 2018. Journal of Medical Biochemistry 38(1). DOI: 2478/jomb-2018-0014. [HbA1c testing]
  157. Yong Xia, Hao Xue, Cunliang Yan, Ling Ji et al. Risk analysis and assessment based on Sigma metrics and intended use. June 2018. Biochemia Medica 28(2). DOI: 11613/BM.2018.020707. [Risk Management]
  158. Victoria Petrides, Sharon Schneider. Using Sigma metrics to establish analytical product performance requirements and optimize analytical performance of an in vitro diagnostic assay using a theoretical total PSA assay as an example. June 2018. Biochemia Medica 28(2). DOI: 11613/BM.2018.020903. [Abbott][PSA testing]
  159. Xiuzhi Guo, Tianjiao Zhang, Xuehui Gao, Xinqi Cheng. Sigma metrics for assessing the analytical quality of clinical chemistry assays: A comparison of two approaches. June 2018. Biochemia Medica 28(2). DOI: 11613/BM.2018.020708. [alternative approaches]
  160. Beatriz Varela, Gonzalo Pacheco Comprehensive evaluation of the internal and external quality control to redefine analytical quality goals. June 2018. Biochemia Medica 28(2). DOI: 11613/BM.2018.020710.
  161. Kumar BV, Mohan T. Sigma metrics as a tool for evaluating the performance of internal quality control in a clinical chemistry laboratory. J Lab Physicians. 2018 Apr-Jun;10(2):194-199. doi: 10.4103/JLP.JLP_102_17. PMID: 29692587 [QC Design]
  162. Sulekha Sinha, Arindam Ghosh, Aritri Bir. ROLE OF SIX SIGMA METRICES IN ASSESSING QUALITY CHECK OF ANALYTICAL ERRORS IN CLINICAL LABORATORY. April 2018. International Journal of Scientific Research 7(4 April 2018).
  163. Fereshteh Atabi, Reza Mohammadi. External Quality Assessment of Glycated Hemoglobin in Iran: Comparison of Five Different Commercial Methods with Two Different Total Allowable Errors. April 2018. Journal of Medical Biochemistry 37(4). DOI: 1515/jomb-2017-0057. [TEa differences]
  164. Usha Adiga, Preethika Ananda. Sigma Metrics of Biochemical Parameters in a Tertiary Care Hospital in Coastal Karnataka. February 2018. Annual Research & Review in Biology 23(3):1-7 DOI: 9734/ARRB/2018/38660.
  165. Ian Baine, Burak Bahar, Christopher Tormey. The Application of Sigma Metrics in Screening for HIV and HCV. January 2018. American Journal of Clinical Pathology 149(suppl_1):S26-S26. DOI:1093/ajcp/aqx116.059.
  166. IQC Laboratory management strategy for medical biology. Bugni E, Cohen R, Mazellier C. Ann Biol Clin (Paris). 2017 Dec 1;75(6):637-645. doi: 10.1684/abc.2017.1290. PMID: 29072175
  167. Cas Weykamp, Carla Siebelder J Diabetes Sci Technol. 2018 Jul;12(4):747-752. doi: 10.1177/1932296817741320. Epub 2017 Nov 17.Evaluation of Performance of Laboratories and Manufacturers Within the Framework of the IFCC model for Quality Targets of HbA1c PMID: 29145735 PMCID: PMC6134299 DOI: 1177/1932296817741320 [HbA1c][alternative calculations]
  168. Ahmed Kaftan, Anne Khazal Yaseen, Zina Hasan. Assessment of sigma metrics results of serum glucose and lipid profile tested by automated chemistry analyzer in medical city hospitals in Iraq. October 2017. International Journal of Research in Medical Sciences 5(11):4690. DOI: 18203/2320-6012.ijrms20174917.
  169. Nar R, Emekli DI. The Evaluation of Analytical Performance of Immunoassay Tests by using Six-sigma Method. J Med Biochem. 2017 Oct 28;36(4):301-308. doi: 10.1515/jomb-2017-0026. eCollection 2017 Oct. PMID: 30581326
  170. Mario Galindo-Méndez, Alaciel Sánchez López. Aplicación de metas analíticas y modelo Seis Sigma en la evaluación del control de calidad de Química Clínica. July 2017. Revista del Laboratorio Clínico 11(1). DOI: 1016/j.labcli.2017.06.008.
  171. Jun Xia, Su-Feng Chen, Fei Xu, Yong-Lie Zhou. Quality specifications of routine clinical chemistry methods based on sigma metrics in performance evaluation. June 2017. Journal of Clinical Laboratory Analysis 32(Pt 1). DOI: 1002/jcla.22284. (TEa differences]
  172. Evaluating new HbA1c methods for adoption by the IFCC and NGSP reference networks using international quality targets. April 2017. Clinical Chemistry and Laboratory Medicine 55(9) DOI: 1515/cclm-2017-0109. Erna Lenters-Westra, Emma English [HbA1c] [International Standard]
  173. Using Sigma Quality Control to Verify and Monitor Performance in a Multi-Instrument, Multisite Integrated Health Care Network. Harrison HH, Jones JB. Clin Lab Med. 2017 Mar;37(1):207-241. doi: 10.1016/j.cll.2016.10.001. Epub 2016 Dec 26. PMID: 28153367
  174. Application of Sigma Metrics Analysis for the Assessment and Modification of Quality Control Program in the Clinical Chemistry Laboratory of a Tertiary Care Hospital. Iqbal S, Mustansar T. Indian J Clin Biochem. 2017 Mar;32(1):106-109. doi: 10.1007/s12291-016-0565-x. Epub 2016 Apr 7. PMID: 28149022 [QC Design]
  175. Jamuna Jairaman, Zarinah Sakiman, Debbie Lee. Sunway Medical Laboratory Quality Control Plans Based on Six Sigma, Risk Management and Uncertainty. March 2017. Clinics in Laboratory Medicine 37(1):163-176. DOI: 1016/j.cll.2016.09.013.
  176. Litten J. Applying Sigma Metrics to Reduce Outliers. Clinics in Laboratory Medicine 37(1) March 2017;37:177–86. 10.1016/j.cll.2016.09.014 - DOI – PubMed [QC Design]
  177. Navapun Charuruks. Sigma Metrics Across the Total Testing Process. December 2016 and March 2017. Clinics in Laboratory Medicine 37(1). DOI: 1016/j.cll.2016.09.009.
  178. Yasemin Üstündağ Application of Sigma Metrics and Performance Comparison Between Two Biochemistry Analyser and A Blood Gas Analyser for the Determination of Electrolytes. February 2017. Journal of Clinical and Diagnostic Research 2017(2):6-9. DOI: 7860/JCDR/2017/23486.9259.
  179. Florian Scherrer 1 , Jean-Pierre Bouilloux 2 , Ors'Anton Calendini  3 , Didier Chamard  4 , François Cornu  5  Interest and limits of the six sigma methodology in medical laboratory. Ann Biol Clin (Paris). 2017 Feb 1;75(1):107-113. doi: 10.1684/abc.2016.1216.  PMID: 28132939 DOI: 1684/abc.2016.1216
  180. Jos Eacute M Maesa, Patricia Fern Aacute Ndez-Riejos, Catalina S, Aacute Nchez-Mora, Mar Iacute A De Toro-Crespo, Concepci Oacute N Gonz Aacute Lez-Rodriguez Clin Lab. 2017 Jan 1;63(1):79-83. Application of Six Sigma Model to Evaluate the Analytical Quality of Four HbA1c Analyzers PMID: 28164511 DOI: 7754/Clin.Lab.2016.160608 [HbA1c]
  181. Nikunj Modi, Tejas J. Shah. Application of Six sigma test in Clinical Biochemistry Laboratory. January 2017. Int J Res Med. 2017; 6(2); 75-78.
  182. Mai Thi Chi Tran 1 , KienTrung Hoang 2 , Ronda F Greaves  3  Practical application of biological variation and Sigma metrics quality models to evaluate 20 chemistry analytes on the Beckman Coulter AU680 Clin Biochem. 2016 Nov;49(16-17):1259-1266. doi: 10.1016/j.clinbiochem.2016.08.008. Epub 2016 Aug 12. PMID: 27527571 DOI: 1016/j.clinbiochem.2016.08.008
  183. Chakravarthy S, Ramanathan S, Smitha S, Vijayakumar KV, Nallathambi T, Micheal S. Phoenix in the lab: The sigma metrics during Chennai's worst disaster: Monitoring and management of the Quality Management System (QMS). Internet Journal of Pathology and Laboratory Medicine. 2017 3 No. 1.
  184. Erna Lenters-Westra, Emma English  Clin Lab Med. 2017 Mar;37(1):57-71. doi: 10.1016/j.cll.2016.09.006. Epub 2016 Dec 14. Understanding the Use of Sigma Metrics in Hemoglobin A1c Analysis. PMID: 28153370 DOI: 1016/j.cll.2016.09.006 [HbA1c]
  185. Andrea M. Cook, Andreas Moritz, Kathleen P. Freeman, Natali Bauer. Quality requirements for veterinary hematology analyzers in small animals—a survey about veterinary experts′ requirements and objective evaluation of analyzer performance based on a meta-analysis of method validation studies: bench top hematology analyzer. Volume45, Issue3, September 2016, Pages 466-476. https://doi.org/10.1111/vcp.12383
  186. Muhammad Shariq Shaikh, B Moiz. Analytical performance evaluation of a high-volume hematology laboratory utilizing sigma metrics as standard of excellence. February 2016. International Journal of Laboratory Hematology 38(2). DOI: 1111/ijlh.12468.
  187. Özlem Gülbahar, Murat Kocabıyık, Mehmed Zahid Çıracı, Mine Taşlıpınar et al. The use of six sigma methodology to evaluate the analytical performances of clinical chemistry analyzers. January 2016. Türk Biyokimya Dergisi / Turkish Journal of Biochemistry 43(1). DOI: 1515/tjb-2016-0223.
  188. Fengfeng Kang 1 , Chuanbao Zhang 2 , Wei Wang  2 , Zhiguo Wang  2  Sigma metric analysis for performance of creatinine with fresh frozen serum Scand J Clin Lab Invest. 2016;76(1):40-4. doi: 10.3109/00365513.2015.1091494. Epub 2015 Oct 8. PMID: 26450266 DOI: 3109/00365513.2015.1091494 [creatinine testing]
  189. Yasemin Üstündağ, kağan Huysal. Application of sigma metrics for the assessment of quality assurance using the MQ-2000 PT HbA1c analyzer. October 2015. Biochemia Medica 25(3). DOI: 11613/BM.2015.042. [HbA1c]
  190. Yang Fei , Wei Wang , Falin He , Kun Zhong , Zhiguo Wang. Evaluating Laboratory Performance on Point-of-Care Glucose Testing with Six Sigma Metric for 151 Institutions in China Diabetes Technol Ther. 2015 Oct;17(10):745-54. doi: 10.1089/dia.2014.0421. Epub 2015 Jun 5. PMID: 26355758 DOI: 1089/dia.2014.0421 [POC]
  191. Manchana Lakshman, Ravindra Reddy, P. Bhulaxmi, Swati Prakasham et al. Evaluation of sigma metrics in a Medical Biochemistry lab. March 2015. International Journal of Biomedical Research 6(3):164. DOI: 10.7439/ijbr.v6i3.1709.
  192. Justice Afrifa, Seth A. Gyekye, William K.B.A. Owiredu, Aaron R. Arthur et al . Application of sigma metrics for the assessment of quality control in clinical chemistry laboratory in Ghana: A pilot study. January 2015. Nigerian Medical Journal 56(1):54-58. DOI: 4103/0300-1652.149172.
  193. Weykamp C, John G, Gillery P, English E, Ji L, Lenters-Westra E, et al. IFCC Task Force on Implementation of HbA1c Standardization. Investigation of two models to set and evaluate quality targets for HbA1c: biological variation and sigma-metrics. Clin Chem. 2015;61:752–9. 10.1373/clinchem.2014.235333 - DOI - PMC – PubMed [HbA1c] [International recognition][alternative calculations]
  194. Adiga US, Preethika A, Swathi K. Sigma metrics in clinical chemistry laboratory: A guide to quality control. Al Ameen J Med Sci 2015; 8(4):281-287. ISSN: 0974-1143.
  195. Lakshman M, Reddy BR, Bhulakshmi P, et al. Evaluation of sigma metrics in a Medical Biochemistry lab. Int J Biomed Rese 2015;6(03): 164-171. DOI: 10.7439/ijbr.
  196. Ercan M, BogdaycIoğlu N, Akbulut E, Oğuz E, Topçuoğlu C, YIlmaz F. Assessment Of The Analytic Performance For Immunassay[stet.] Tests With Six Sigma Methodology: T425. Clin Chem Laboratory Med 2015;53.
  197. Chuanbao Zhang, Haijian Zhao, Jing Wang, Jie Zeng, Zhiguo Wang The Application of Six Sigma Techniques in the Evaluation of Enzyme Measurement Procedures in China Clin Lab. 2015;61(5-6):461-5. doi: 10.7754/clin.lab.2014.140915. PMID: 26118176 DOI: 7754/clin.lab.2014.140915
  198. Gulbahar O, Arslan B, Sen B, Cingirt M, Yılmaz S. Evaluation of thyroid function tests in our laboratory by using six sigma analysis. Turk J Biochem 2015;40(S1).
  199. Francesco Cian , Elisabeth Villiers, Joy Archer, Francesca Pitorri, Kathleen Freeman. Use of Six Sigma Worksheets for assessment of internal and external failure costs associated with candidate quality control rules for an ADVIA 120 hematology analyzer. Vet Clin Pathol 2014 Jun;43(2):164-71. doi: 10.1111/vcp.12141. Epub 2014 Apr 21. PMID: 24750485 DOI: 10.1111/vcp.12141 https://pubmed.ncbi.nlm.nih.gov/39326693/ [benchmarking] [QC design] [veterinary laboratory]
  200. Seema Shah, Dr Reetika Saini, Dr Sangeeta B. Singh, Anil Kumar Goel et al. Six Sigma Metrics and Quality Control in Clinical Laboratory. April 2014. International Journal of Medical Research and Review 2(2):140-149. DOI: 17511/ijmrr.2014.i02.20.
  201. Sunil Nanda, Lopamudra Ray. Quantitative Application of Sigma Metrics in Medical Biochemistry. December 2013. Journal of Clinical and Diagnostic Research 7(12):2689-91. DOI: 7860/JCDR/2013/7292.3700.
  202. Bhakti Gami, Dharmik S. Patel, Kiran Chauhan, N Haridas. SIGMA METRICS AS A QUALITY MARKER FOR ANALYZING ELECTROLYTES IN LABORATORY. September 2013. International Journal of Advanced Research 1(7):197-201
  203. . Husniza Hussain 1 , Norhayati Mustafa Khalid, Rusidah Selamat, Wan Mohamud Wan Nazaimoon. Evaluation of the performance of a micromethod for measuring urinary iodine by using six sigma quality metrics. Ann Lab Med. 2013 Sep;33(5):319-25. doi: 10.3343/alm.2013.33.5.319. Epub 2013 Aug 8. PMCID: PMC3756235 DOI: 3343/alm.2013.33.5.319 [urinary iodine]
  204. Chaudhary NG, Patani SS, Sharma H, et al. Application of six sigma for the quality assurance in clinical biochemistry laboratory: A retrospective study. Int J Res Med 2013;2(3):17-20. ISSN: 2320-2742.
  205. Vesna Supak Smolcic, Lidija Bilic-Zulle. Normalized MEDx chart as a useful tool for evaluation of analytical quality achievements. A picture is worth a thousand words. December 2012. Clinical Chemistry and Laboratory Medicine 51(5):1-3. DOI: 1515/cclm-2012-0629.
  206. Emma Hooijberg, Ernst Leidinger, and Kathleen P. Freeman. An error management system in a veterinary clinical laboratory. Journal of Veterinary Diagnostic Investigation, Volume 24, Issue 3, May 2012, Pages 458-468 https://doi.org/10.1177/1040638712441782
  207.  Schoenmakers CH, Naus AJ, Vermeer HJ, van Loon D, Steen G.  Practical application of Sigma Metrics QC procedures in clinical chemistry. Clin Chem Lab Med. 2011 Nov;49(11):1837-43. doi: 10.1515/CCLM.2011.249. Epub 2011 Jul 29. PMID: 21801029 [QC Design]
  208. Bhawna Mahajan, Binita Goswami, Vinod K Gupta, Venkatesan Mallika et al Application of Sigma Metrics for the Assessment of Quality Assurance in Clinical Biochemistry Laboratory in India: A Pilot Study. April 2011. Indian Journal of Clinical Biochemistry 26(2):131-5. DOI: 1007/s12291-010-0083-1.
  209. Quality Control Validation, Application of Sigma Metrics, and Performance Comparison between Two Biochemistry Analyzers in a Commercial Veterinary Laboratory. Alison J Farr, Kathleen P Freeman. October 2008. Journal of veterinary diagnostic investigation: official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc 20(5):536-44. DOI: 1177/104063870802000502. [veterinary laboratory]
  210. Alison J Farr, Kathleen P Freeman.  Quality control validation, application of sigma metrics, and performance comparison between two biochemistry analyzers in a commercial veterinary laboratory J Vet Diagn Invest. 2008 Sep;20(5):536-44. doi: 10.1177/104063870802000502. PMID: 18776084 DOI: 10.1177/104063870802000502
  211. Jérémie M Gras, Marianne Philippe. Application of the Six Sigma concept in clinical laboratories: A review. February 2007. Clinical Chemistry and Laboratory Medicine 45(6):789-96. DOI: 1515/CCLM.2007.135.
  212. Svetlana Ignjatovic, Majkić-Singh Nada. Application of six sigma in control of health laboratories. January 2007. Journal of Medical Biochemistry 26(3).
  213. Mariana Lipp Haussen, Fernando Berlitz. Seis sigma no laboratório clínico: impacto na gestão de performance analítica dos processos técnicos - Six sigma in clinical laboratory: impact in analytical performance management of technical process. October 2005. Jornal Brasileiro de Patologia e Medicina Laboratorial 41(5). DOI: 1590/S1676-24442005000500004.
  214. Diler Aslan, Süleyman Demir.  Laboratuvar Tıbbında Altı-Sigma Kalite Yönetimi . Türk Biyokimya Dergisi [Turkish Journal of Biochemistry - Turk J Biochem] 2005; 30 (4); 272-278. 2005. http://www.TurkJBiochem.com ISSN 1303-829X (electronic) 0250-4685 (printed)
  215. Garber C. Six Sigma: its role in the clinical laboratory. Clin Lab News. 2004;4:10-4.

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