Utility of self-report antiretroviral adherence for predicting HIV viral load among persons who inject drugs in Hai Phong Vietnam: assessing differences by methamphetamine use

ABSTRACT

In resource-limited settings, alternatives to HIV viral load testing may be necessary to monitor the health of people living with HIV. We assessed the utility of self-report antiretroviral therapy (ART) to screen for HIV viral load among persons who inject drugs in Hai Phong Vietnam, and consider differences by recent methamphetamine use. From 2016 to 2018 we recruited PWID through cross sectional surveys and collected self-report ART adherence and HIV viral load to estimate sensitivity, specificity, positive and negative predictive values (PPV, NPV) and likelihood ratios (LR+, LR-) for self-reported ART adherence as a screening test for HIV viral load. We used three HIV viral load thresholds: < 1000, 500 and 250 copies/mL; laboratory-confirmed HIV viral load was the gold standard. Among 792 PWID recruited, PPV remained above 90% regardless of recent methamphetamine use with slightly higher PPV among those not reporting recent methamphetamine use. The results remained consistent across all three HIV viral load thresholds. Our findings suggest that when HIV viral load testing is not possible, self-reported ART adherence may inform decisions about how to prioritize HIV viral load testing among PWID. The high PPV values suggest self-reported high ART adherence indicates likely HIV viral suppression, irrespective of methamphetamine use.

KEYWORDS:

• Positive predictive value (PPV)
• negative predictive value (NPV)
• likelihood ratio
• methamphetamine
• HIV/AIDS
• antiretroviral therapy (ART)

Acknowledgements

We would like to thank the community-based organization members in Hai Phong who were vital in the recruitment and retention of participants in the cohort, administering questionnaires to participants in the study, and promoting harm reduction activities and ART initiation and retention for our participants living with HIV in the cohort.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by grants from NIDA (US) 1R01DA041978 and ANRS (France) 12299.