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Validation of the Viral Load Testing Criteria – an algorithm for targeted viral load testing in HIV‐positive adults receiving antiretroviral therapy
Author(s) -
Thorman Johannes,
Björkman Per,
Tesfaye Fregenet,
Jeylan Asiya,
Balcha Taye Tolera,
Reepalu Anton
Publication year - 2019
Publication title -
tropical medicine and international health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.056
H-Index - 114
eISSN - 1365-3156
pISSN - 1360-2276
DOI - 10.1111/tmi.13201
Subject(s) - viral load , medicine , algorithm , antiretroviral therapy , human immunodeficiency virus (hiv) , immunology , computer science
Objectives Restricted capacity for viral load ( VL ) testing is a major obstacle for antiretroviral therapy ( ART ) programmes in high‐burden regions. Algorithms for targeted VL testing could help allocate laboratory resources rationally. We validated the performance of the Viral Load Testing Criteria ( VLTC ), an algorithm with satisfactory performance in derivation (sensitivity 91%, specificity 43%). Methods HIV ‐positive adults who had been receiving first‐line ART for ≥12 months at three Ethiopian public ART clinics were included. Healthcare providers collected data on variables of the VLTC : current CD 4 count, mid‐upper arm circumference ( MUAC ) and self‐reported treatment interruption. VL testing was performed in parallel. Performance of the algorithm for identification of patients with VL ≥ 1000 copies/ml was evaluated. Results Of 562 patients (female 62%, median ART duration 92 months), 33 (6%) had VL ≥ 1000 copies/ml. Sensitivity for the VLTC was 85% (95% CI , 68–95), specificity 60% (95% CI , 55–64), positive predictive value 12% (95% CI , 10–14) and negative predictive value 98% (95% CI , 97–99). Use of the algorithm would reduce the number of VL tests required by 57%. Misclassification occurred in 5/33 (15%) of subjects with VL ≥ 1000 copies/ml. Conclusion In validation, the VLTC performed similarly well as derivation. Use of the VLTC may be considered for targeted VL testing for ART monitoring in high‐burden regions.