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Duplicate analysis method: a cheaper alternative to commercial IQC materials in limited resource settings for monitoring CD4 testing.

Shete A, Singh DP, Mahajan B, Kokare A, Paranjape R, Thakar M - AIDS Res Ther (2015)

Bottom Line: There was good match between r(2) values and % CV of the laboratories performing both the types of QC methods.Commercially available controls showed limitations such as altered specimen quality leading to difficulties in manual gating and issues with the establishment of laboratory range.Duplicate analysis can serve as a cheaper alternative to commercially available controls for IQC of CD4 testing especially when supplemented with other QC measures for controlling variations caused by reagent, equipment, staff and environment in addition to the successful participation in External Quality Assurance programme.

View Article: PubMed Central - PubMed

Affiliation: National AIDS Research Institute, 73 G Block MIDC Bhosari, Pune, 411026 India.

ABSTRACT

Background: India has a large number of HIV infected patients being followed up at anti-retroviral therapy (ART) centers. The patients are regularly offered CD4 count estimation for deciding their eligibility for ART initiation as well as for monitoring response to ART, making CD4 count estimation a very critical test. Hence, quality control of CD4 testing is utmost important for ultimate success of ART program. As the commercial controls are very expensive, internal quality control (IQC), at present, is being done by duplicate analysis method using previous day samples in most of the laboratories. Hence the study was undertaken to review performance of duplicate analysis method for monitoring daily IQC.

Methods: Quality control (QC) data from 11 Indian laboratories using duplicate analysis and/or commercial controls for IQC of CD4 testing was collected for reviewing information on QC parameters such as precision, accuracy and trend monitoring. Precision was determined by r(2) values and mean % variation for duplicate analysis and coefficient of variation (% CV) for commercial controls. Accuracy was monitored by rate of QC failures for both the types of control and trend monitoring was done by plotting LJ charts for commercial controls and by plotting daily % variation for duplicate analysis.

Results: The laboratories using duplicate analysis for IQC showed good precision with mean % variation ranging from 0.5 to 7.2. There was good match between r(2) values and % CV of the laboratories performing both the types of QC methods. Rates of QC failures were 2.3 for duplicate analysis and 3 per laboratory-year for IMMUNO-TROL controls. Daily trend monitoring showed fluctuation of daily counts around mean in LJ charts and of percent variation around 0% in duplicate analysis method. Commercially available controls showed limitations such as altered specimen quality leading to difficulties in manual gating and issues with the establishment of laboratory range.

Conclusion: Duplicate analysis can serve as a cheaper alternative to commercially available controls for IQC of CD4 testing especially when supplemented with other QC measures for controlling variations caused by reagent, equipment, staff and environment in addition to the successful participation in External Quality Assurance programme.

No MeSH data available.


Related in: MedlinePlus

Manufacturer’s range (MR) versus laboratory established ranges (LR) for commercial controls for CD4+ T cells. The ranges (mean ± 2 SD) for different lots of the commercial controls available in different months are plotted. Y axis represents CD4 counts and X axis represents months of the range establishment. Blue bars indicate manufacturer’s ranges and purple bars indicate laboratory established ranges. The yellow triangle in the middle of each bar indicates mean values.
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Fig5: Manufacturer’s range (MR) versus laboratory established ranges (LR) for commercial controls for CD4+ T cells. The ranges (mean ± 2 SD) for different lots of the commercial controls available in different months are plotted. Y axis represents CD4 counts and X axis represents months of the range establishment. Blue bars indicate manufacturer’s ranges and purple bars indicate laboratory established ranges. The yellow triangle in the middle of each bar indicates mean values.

Mentions: Since commercially available controls come with manufacturer’s range, they give some idea about the accuracy of the results. But they may not give the exact information about the accuracy as the range is wide as shown in Fig. 5 and it is advisable to establish laboratory range based on its own mean and standard deviation (SD). It was not feasible for most of the laboratories using multi-check controls to establish their own range because of their short expiry leading to false estimate of accuracy. Establishing provisional range based on 10 measurements and then subsequently using 20 data points for establishing the final range [10] would be more appropriate monitoring daily QC in such case.Fig. 5


Duplicate analysis method: a cheaper alternative to commercial IQC materials in limited resource settings for monitoring CD4 testing.

Shete A, Singh DP, Mahajan B, Kokare A, Paranjape R, Thakar M - AIDS Res Ther (2015)

Manufacturer’s range (MR) versus laboratory established ranges (LR) for commercial controls for CD4+ T cells. The ranges (mean ± 2 SD) for different lots of the commercial controls available in different months are plotted. Y axis represents CD4 counts and X axis represents months of the range establishment. Blue bars indicate manufacturer’s ranges and purple bars indicate laboratory established ranges. The yellow triangle in the middle of each bar indicates mean values.
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4536604&req=5

Fig5: Manufacturer’s range (MR) versus laboratory established ranges (LR) for commercial controls for CD4+ T cells. The ranges (mean ± 2 SD) for different lots of the commercial controls available in different months are plotted. Y axis represents CD4 counts and X axis represents months of the range establishment. Blue bars indicate manufacturer’s ranges and purple bars indicate laboratory established ranges. The yellow triangle in the middle of each bar indicates mean values.
Mentions: Since commercially available controls come with manufacturer’s range, they give some idea about the accuracy of the results. But they may not give the exact information about the accuracy as the range is wide as shown in Fig. 5 and it is advisable to establish laboratory range based on its own mean and standard deviation (SD). It was not feasible for most of the laboratories using multi-check controls to establish their own range because of their short expiry leading to false estimate of accuracy. Establishing provisional range based on 10 measurements and then subsequently using 20 data points for establishing the final range [10] would be more appropriate monitoring daily QC in such case.Fig. 5

Bottom Line: There was good match between r(2) values and % CV of the laboratories performing both the types of QC methods.Commercially available controls showed limitations such as altered specimen quality leading to difficulties in manual gating and issues with the establishment of laboratory range.Duplicate analysis can serve as a cheaper alternative to commercially available controls for IQC of CD4 testing especially when supplemented with other QC measures for controlling variations caused by reagent, equipment, staff and environment in addition to the successful participation in External Quality Assurance programme.

View Article: PubMed Central - PubMed

Affiliation: National AIDS Research Institute, 73 G Block MIDC Bhosari, Pune, 411026 India.

ABSTRACT

Background: India has a large number of HIV infected patients being followed up at anti-retroviral therapy (ART) centers. The patients are regularly offered CD4 count estimation for deciding their eligibility for ART initiation as well as for monitoring response to ART, making CD4 count estimation a very critical test. Hence, quality control of CD4 testing is utmost important for ultimate success of ART program. As the commercial controls are very expensive, internal quality control (IQC), at present, is being done by duplicate analysis method using previous day samples in most of the laboratories. Hence the study was undertaken to review performance of duplicate analysis method for monitoring daily IQC.

Methods: Quality control (QC) data from 11 Indian laboratories using duplicate analysis and/or commercial controls for IQC of CD4 testing was collected for reviewing information on QC parameters such as precision, accuracy and trend monitoring. Precision was determined by r(2) values and mean % variation for duplicate analysis and coefficient of variation (% CV) for commercial controls. Accuracy was monitored by rate of QC failures for both the types of control and trend monitoring was done by plotting LJ charts for commercial controls and by plotting daily % variation for duplicate analysis.

Results: The laboratories using duplicate analysis for IQC showed good precision with mean % variation ranging from 0.5 to 7.2. There was good match between r(2) values and % CV of the laboratories performing both the types of QC methods. Rates of QC failures were 2.3 for duplicate analysis and 3 per laboratory-year for IMMUNO-TROL controls. Daily trend monitoring showed fluctuation of daily counts around mean in LJ charts and of percent variation around 0% in duplicate analysis method. Commercially available controls showed limitations such as altered specimen quality leading to difficulties in manual gating and issues with the establishment of laboratory range.

Conclusion: Duplicate analysis can serve as a cheaper alternative to commercially available controls for IQC of CD4 testing especially when supplemented with other QC measures for controlling variations caused by reagent, equipment, staff and environment in addition to the successful participation in External Quality Assurance programme.

No MeSH data available.


Related in: MedlinePlus