Comparative Analysis of External Quality Assessment Results from Dimension EXL 200 and VITROS® 4600 BC09-BC12
Dr. Kanchan Kulhari,
Base Hospital Delhi Cantt, Dhaula Kuan, Delhi Cantt, Delhi-110010, India.
Introduction: In order to maintain a strict control over the results generated in clinical chemistry laboratories, a number of procedures are followed to maintain the quality of results. The procedures followed in order to compare the performances between different laboratories are known as External Quality Assessment (EQA). Separate EQA programmes for different analysers are recommended as the methods and principles may be different for them.
Aim: To compare the performance of EQA results from Dimension EXL 200 and VITROS® 4600 analysers from two consecutive years and to analyse differences, if any.
Materials and Methods: The clinical chemistry laboratory of this tertiary care hospital is enrolled in EQA with CMC Vellore. The lab has Dimension EXL 200 and VITROS® 4600 analysers. The results from two different EQA cycles of 2016 (Dimension EXL 200) and 2017 (VITROS® 4600) have been for analysed and compared. The Variable Index Score (VIS) and Standard Deviation Index (SDI) from these reports were analysed.
Results: The data for 2016 for Dimension EXL 200 had 15 parameters in the EQA while VITROS® 4600 had 20 parameters in the EQA list. There were some parameters that were not common and hence have not been compared. The overall VIS for the Dimension had 07 parameters (46.7%) VIS (<100) ‘very good’, 05 (33%) VIS (100-150) ‘good category’, 02 (13%) VIS (151-200) in ‘satisfactory’ and 01 (07%) parameter had VIS (>200) ‘not acceptable’ category. The overall VIS for the VITROS® 4600 had 15 parameters (75%) with VIS (<100) ‘very good’, 04 (20%) with VIS (100-150) ‘good category’, 01 (13%) with VIS (151-200) in ‘satisfactory’ category. The SDI of the same parameters on both the equipments were similar with DIMENSION having 12 (86%) and VITROS 4600 having 11 (79%) results in the ‘excellent’ category while each had a single parameter in the ‘accept with caution’ category with no parameter requiring any corrective action.
Conclusion: The VIS results from the VITROS® 4600 as compared to Dimension EXL 200 showed marked improvement with 71.4% parameters undergoing a reduction in the VIS values while the SDI results were mostly similar.