Table 1

Summary of monitoring strategies (clinical, immunological and viral load) evaluated in HIV simulation studies

YearSettingModelMonitoring strategiesTiming and frequencyHealth outcomesReference
2010Côte d'IvoireCEPAC (IBM)ClinicalEntry into care, presentation of acute event and at 3-month intervalsSurvival (life expectancy)40
ImmunologicalEntry into care and at 6-month intervals
VirologicEntry into care and at 6-month intervals
2016ZimbabweHIV synthesis model (IBM)ImmunologicalAt 12-month intervalsDALYs29
VirologicAt 12-month intervals
Adherence monitoring-based interventionsAt 12-month intervals
Virologic+adherence-based interventionsAt 12-month intervals
2008Lower income countriesHIV synthesis model (IBM)ClinicalAt 6-month intervals (WHO 3/4 clinical stages)*Survival (mean life years lived)38
ImmunologicalAt 6-month intervals (50%–33% decline)*Proportion of resistance (to NVP, 3TC, d4T, etc)
VirologicAt 6-month intervals (≥10 000 and 500 copies/mL)*
2011Sub-Saharan AfricaStochastic computer simulation (IBM)ClinicalNew WHO clinical stage 4 condition at least 9 months after start of ART determines the need to switchNew HIV transmissions+drug resistance28
VirologicAt 6-month intervals (>500 copies/mL)*Death rate
2016ZimbabweStochastic (IBM)ClinicalAt 3-month intervalsDALYs40
Virologic (POC)At 6-month intervals
2013South Africa, Malawi and ZambiaStochastic computer simulation (IBM)ImmunologicalAt 6-month intervals, with targeted CD4/VL (<100 or 50% decline)*Mortality rates26
VirologicAt 6-month intervals, with targeted CD4/VL (≥1000 copies/mL)*
2015South AfricaCompartmentalClinicalAt 3-month intervalsDALYs31
ImmunologicalAt 6, 12 and 24-month intervals, with/out targeted VL
Virologic (POC)At 6, 12 and 24-month intervals
VirologicAt 6, 12 and 24-month intervals
2017South Africa†Stochastic simulation (IBM)VirologicOne VL measurement (duration on ART/gestational age)Predicting VL at delivery36
2016VietnamCompartmentalVirologicAt 6 and 12-month intervals, varying levels of coverageBurden of drug resistance34
2014ZimbabweHIV synthesis model (IBM)ClinicalAt 3-month intervals+targeted VL/drug resistance testingDeath27
ImmunologicalAt 6-month intervals+targeted VL/drug resistance testingHIV incidence
VirologicWHO timing+targeted VL/drug resistance testingDALYs
Drug resistance testingAt time of first ART failure
2014South Africa‡Stochastic (IBM)ImmunologicalAt 6-month intervalsMortality37
VirologicAt 6 and 12-month intervals
2016Cote d’IvoireCEPAC (IBM)ImmunologicalAt 6 and 12-month intervals+CD4/VL confirmatory testingTime spent on failing treatment35
VirologicAt 6 and 12-month intervals+CD4/VL confirmatory testingLife expectancy
2012South AfricaStochastic (IBM)ImmunologicalAt 6-month intervalsHIV incidence39
VirologicAt 6-month intervals
  • *Failure definition/threshold for switching ART.

  • †Pregnant women.

  • ‡Paediatric study population.

  • ART, antiretroviral therapy; CEPAC, Cost-Effectiveness of Preventing AIDS Complications International model; DALY, disability-adjusted life year; d4T, stavudine; IBM, individual-based model; NVP, nevirapine; POC, point-of-care viral load testing; 3TC, lamivudine; VL, viral load.