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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 12/5/24
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. 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.
  2. 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]
  3. 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]
  4. 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.
  5. 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]
  6. 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]
  7. 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.
  8. 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]
  9. 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]
  10. 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]
  11. 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]
  12. 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]
  13. 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]
  14. 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]
  15. 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]
  16. 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]
  17. 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]
  18. 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]
  19. 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.
  20. 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.
  21. 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.
  22. 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]
  23. 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.

  24. 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]

  25. 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]
  26. 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
  27. 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]
  28. 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]
  29. 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.
  30. 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]
  31. 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.
  32. 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]
  33. 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
  34. 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]
  35. 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.
  36. 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.
  37. 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.
  38. 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.
  39. 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
  40. 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]
  41. 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.
  42. 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.
  43. 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]
  44. 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
  45. 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]
  46. 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]
  47. 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]
  48. 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.
  49. 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.
  50. 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.
  51. 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]
  52. 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]
  53. 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]
  54. 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]
  55. 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]
  56. 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
  57. 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.
  58. 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.
  59. 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
  60. 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]
  61. 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]
  62. 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]
  63. 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.
  64. 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.
  65. 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.
  66. 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]
  67. 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
  68. 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]
  69. 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 ]
  70. 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]
  71. 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]
  72. 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]
  73. 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.
  74. 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]
  75. 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]
  76. 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]
  77. 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.
  78. 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]
  79. 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.
  80. 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.
  81. 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
  82. 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]
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