Dataset Information

Can visual interpretation of NucliSens graphs reduce the need for repeat viral load testing?

ABSTRACT:

Background

In Zimbabwe, viral load (VL) testing for people living with HIV on antiretroviral therapy is performed at the National Microbiology Reference Laboratory using a NucliSens machine. Anecdotal evidence has shown that invalid graphs for "Target Not Detectable (TND)" will upon repeat VL testing produce a valid result for virus not detected, therefore removing the need to repeat the test. This needs formal assessment.

Objectives

To determine i) intra- and inter-rater agreement of the visual interpretation of NucliSens graphs (Target Detectable [TD], TND and No Line [NL]) between two laboratory scientists and ii) sensitivity, specificity and predictive values of the NucliSens graphs compared with repeat VL results.

Method

Cross sectional study using secondary data. Two laboratory scientists independently rated graphs one week apart for intra-rater agreement and compared final ratings with each other for inter-rater agreement. Consensus interpretations of graphs were compared with repeat VL results. Kappa coefficients were used to obtain measures of agreement.

Results

There were 562 patients with NucliSens graphs and repeat VL. Kappa scores were: 0.98 (Scientist A); 0.99 (Scientist B); 0.96 (Scientist A versus Scientist B); and 0.65 (NucliSens graphs versus VL). Sensitivity, specificity, positive predictive value and negative predictive value for graphs compared with VL were 71%, 92%, 79% and 89% respectively.

Conclusion

Intra-and inter-rater agreements were almost perfect. The negative predictive value translates to a false negative rate of 11%. If repeat VL testing is not done, the clinical consequences need to be balanced against cost savings and the risks outweigh the benefits.

SUBMITTER: Handireketi N

PROVIDER: S-EPMC6867593 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

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Publications

Can visual interpretation of NucliSens graphs reduce the need for repeat viral load testing?

Handireketi Newten N Timire Collins C Shewade Hemant Deepak HD Munemo Ellen E Nyagupe Charles C Chipuka Sandra S Sisya Lucia L Gumbo Hlanai H Dhitima Ezekiel E Harries Anthony D AD

PloS one 20191120 11

<h4>Background</h4>In Zimbabwe, viral load (VL) testing for people living with HIV on antiretroviral therapy is performed at the National Microbiology Reference Laboratory using a NucliSens machine. Anecdotal evidence has shown that invalid graphs for "Target Not Detectable (TND)" will upon repeat VL testing produce a valid result for virus not detected, therefore removing the need to repeat the test. This needs formal assessment.<h4>Objectives</h4>To determine i) intra- and inter-rater agreemen ...[more]

PMID: 31747448

Similar Datasets

Project description:BackgroundSince the scale-up of routine viral load (VL) testing started in 2016, there is limited evidence on VL suppression rates under programmatic settings and groups at risk of non-suppression. We conducted a study to estimate VL non-suppression (> 1000 copies/ml) and its risk factors using "routine" and "repeat after enhanced adherence counselling (EAC)" VL results.MethodsWe conducted an analytic cross-sectional study using secondary VL testing data collected between 2014 and 2018 from a centrally located laboratory. We analysed data from routine tests and repeat tests after an individual received EAC. Our outcome was viral load non-suppression. Bivariable and multivariable logistic regression was performed to identify factors associated with having VL non-suppression for routine and repeat VL.ResultsWe analysed 103,609 VL test results (101,725 routine and 1884 repeat test results) collected from the country's ten provinces. Of the 101,725 routine and 1884 repeat VL tests, 13.8% and 52.9% were non-suppressed, respectively. Only one in seven (1:7) of the non-suppressed routine VL tests had a repeat test after EAC. For routine VL tests; males (vs females, adjusted odds ratio (aOR) = 1.19, [95% CI 1.14-1.24]) and adolescents (10-19 years) (vs adults (25-49 years), aOR = 3.11, [95% CI 2.9-3.31]) were more at risk of VL non-suppression. The patients who received care at the secondary level (vs primary, aOR = 1.21, [95% CI 1.17-1.26]) and tertiary level (vs primary, aOR = 1.63, [95% CI 1.44-1.85]) had a higher risk of VL non-suppression compared to the primary level. Those that started ART in 2014-2015 (vs < 2010, aOR = 0.83, [95% CI 0.79-0.88]) and from 2016 onwards (vs < 2010, aOR = 0.84, [95% CI 0.79-0.89]) had a lower risk of VL non-suppression. For repeat VL tests; young adults (20-24 years) (vs adults (25-49 years), (aOR) = 3.48, [95% CI 2.16 -5.83]), adolescents (10-19 years) (vs adults (25-49 years), aOR = 2.76, [95% CI 2.11-3.72]) and children (0-9 years) (vs adults (25-49 years), aOR = 1.51, [95% CI 1.03-2.22]) were at risk of VL non-suppression.ConclusionClose to 90% suppression in routine VL shows that Zimbabwe is on track to reach the third UNAIDS target. Strategies to improve the identification of clients with high routine VL results for repeating testing after EAC and ART adherence in subpopulations (men, adolescents and young adolescents) at risk of viral non-suppression should be prioritised.

Project description:BackgroundWorld Health Organization guidelines now recommend routine use of viral load testing, where available, for patients receiving antiretroviral treatment (ART). However, its use has not been routinely implemented in many resource-limited settings due to cost, availability and accessibility. Viral load testing is complex, making its application in resource-limited settings challenging. We describe the issues encountered by Médecins Sans Frontières (MSF) when using routine viral load testing in a large HIV programme in sub-Saharan Africa.MethodsBetween October 2005 and August 2006, more than 1200 patients on ART had viral load tests at baseline and at three-month intervals performed by a local reference laboratory that was quality assured by an experienced international institution. Concerns with reliability of results halted testing. The quality control measures instituted with a second laboratory and outcomes of these were documented.ResultsIn 2005 and 2006, only 178 of 334 (53%) previously ART-naïve patients tested after six to 12 months of treatment had viral loads of less than 1000 copies/mL. Similar MSF programmes elsewhere demonstrated virological suppression rates of more than 85%, and duplicate testing showed unacceptable discordance. Laboratory problems encountered included: disregarded quality control; time delays; requirement for retesting; and duplicate sample variations. Potentially harmful clinical outcomes of inaccurate viral load results include: unnecessary ART regimen changes; unnecessary enhanced adherence counselling after "false failures"; and undetected virological failure.ConclusionsViral load testing performed without rigorous quality control carries the risk of erroneous and potentially damaging results. Viral load testing should be utilized only if robust quality assurance has been implemented. Our experience in this and other settings led to the development of a guide for assessing the suitability of a laboratory for viral load testing that can be used to help achieve reliable results.

Dataset Information

Can visual interpretation of NucliSens graphs reduce the need for repeat viral load testing?

Background

Objectives

Method

Results

Conclusion

Publications

Can visual interpretation of NucliSens graphs reduce the need for repeat viral load testing?

Similar Datasets

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