Retrospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Methodol. Nov 29, 2018; 8(3): 44-50
Published online Nov 29, 2018. doi: 10.5662/wjm.v8.i3.44
Assessment of quality control system by sigma metrics and quality goal index ratio: A roadmap towards preparation for NABL
Monica Verma, Kiran Dahiya, Veena Singh Ghalaut, Vasudha Dhupper
Monica Verma, Kiran Dahiya, Veena Singh Ghalaut, Vasudha Dhupper, Department of Biochemistry, Pt. B.D. Sharma, University of Health Sciences, Rohtak 124001, Haryana, India
Author contributions: Verma M designed the research, interpreted the results, and drafted the manuscript; Dahiya K and Ghalaut VS helped in statistical analysis, critical revision, and final approval of the article; Ghalaut VS and Dhupper V helped in making critical revisions and final approval of the article.
Conflict-of-interest statement: None exists.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author to: Monica Verma, DNB, MBBS, MD, Assistant Professor, Doctor, Department of Biochemistry, Pt. B.D. Sharma, University of Health Sciences, House No. 315, 3rd Floor, Model Town, Rohtak 124001, Haryana, India. monisoni26@gmail.com
Telephone: +91-98-13334543
Received: July 31, 2018
Peer-review started: July 31, 2018
First decision: August 20, 2018
Revised: September 4, 2018
Accepted: October 17, 2018
Article in press: October 17, 2018
Published online: November 29, 2018
ARTICLE HIGHLIGHTS
Research background

Accreditation is a formal recognition from a third party body, which demonstrates the competence and capability to carry out a certain task it is claiming to do.

Research motivation

Over 60% of tests are carried out under clinical biochemistry section; hence it plays a critical role in diagnosing and managing diseases. It is imperative to follow a proper quality management system by the laboratory so as to provide accurate and reliable reports in an agreed upon time frame.

Research objectives

Assessment of the analytical phase of quality control system by sigma metrics and quality goal index ratio (QGI).

Research methods

This retrospective study was conducted at the Clinical Biochemistry Laboratory, PGIMS, Rohtak, which recently became a National Accreditation Board for Testing and Calibration of Laboratories (NABL) accredited lab per the International Organization for Standardization (ISO) 15189:2012 and provides service to a > 1700-bed tertiary care hospital. Data of 16 analytes were extracted over a period of one year from January 2017 to December 2017 for calculation of precision, accuracy, sigma metrics, total error, and QGI.

Research results

The average coefficient of variation of all the parameters was below 5%, reflecting precision. The sigma metrics for level 2 indicated that five of the sixteen parameters fell short of meeting minimal Six Sigma quality performance. For level 3, the data collected indicated three of the parameters do not achieve minimal Six Sigma quality performance. QGI ratio indicated that the main problems were inaccuracy in the case of total cholesterol, aspartate transaminase, and alanine transaminase (QGI > 1.2), imprecision in the case of urea (QGI < 0.8), and imprecision and inaccuracy for glucose.

Research conclusions

On the basis of sigma metrics and QGI, it may be concluded that the Clinical Biochemistry Laboratory, PGIMS, Rohtak was able to achieve satisfactory results with world class performance for many analytes one year preceding the NABL accreditation as per ISO standard 15189:2012.

Research perspectives

Although sigma metrics is a well-known industrial standard, it might not be applied universally for all the analytes.