Table 1: Description of models with calculated ART effectiveness.

Study Setting Parameters Art effectiveness
1. Williams, et al. [47] (SACEMA model)

Southern Africa

• Proportion on ART virally suppressed: 90%

• Reduction in transmission on ART

*virally suppressed 96%

*not virally suppressed 88%

• Full coverage (2020): People at risk tested on average twice a year and started on treatment immediately

Effectiveness: 86%

Calculations (for 2020):

On ART: 90%

Not on ART: 10%

Of those on ART percentage virally suppressed: 90%

Of those on ART percentage not virally suppressed: 10%

On ART and virally suppressed transmission reduced: 96%

On ART and not virally suppressed transmission reduced: 88%

Effectiveness = 1- (Proportion on ART (Proportion on ART virally suppressed × transmission on ART and virally suppressed + Proportion on ART not virally suppressed × transmission on ART not virally suppressed) + Not on ART)

Equation: 1 - (0.9 × (0.9 × 0.04 + 0.1 × 0.12) + 0.1) = 0.86

2. Smith, et al. [48] (Imperial model)

South Africa

• Efficacy (protection afforded by perfect use of a product) of early ART: 85%

• Effective coverage (proportion of people who fully adhere to a product such that they benefit from its protection): Constant: 0%; medium: 40%; maximum: 60%

Effectiveness: 51%

Calculations (for 2020):

On ART: 60%

Not on ART: 40%

On ART transmission reduced: 85%

Effectiveness = 1- (On ART × transmission on ART + proportion not on ART)

Equation: 1- (0.6 × 0.15 + 0.4) = 0.51

3. McGillen, et al. [49] (Imperial model) 18 countries from sub-Saharan Africa (80% of adult HIV burden in the region)

• Effectiveness of early ART as prevention (reduction in risk of onward transmission): 70%

• Note: Early ART refers to a prevention method comprising outreach testing programmes and the offer of treatment to all PLHIV.

• Achievable coverage: 33% among heterosexual men and low-risk women and 66% among MSM and FSW (this is the coverage of early ART for PLHIV who have not already presented for care i.e. their CD4 is above 200 initially and above 350 later when ART eligibility shifted)

• Proportion of people living with HIV who are virally suppressed: 63%

Effectiveness: 44%

Calculations (for 2020):

On ART: NA

Not on ART: NA

On ART virally suppressed: 63%

On ART not virally suppressed: NA

On ART transmission reduced: 70%

Effectiveness = 1- (proportion on ART and suppressed × transmission on ART and suppressed + proportion not on ART)

Equation: 1- (0.63 × 0.3 + 0.37) = 0.44

4. Stover, et al. [26] (GOALS model)

45 countries (86% of new infections globally)

• 95% reduction in infectiousness among those virally suppressed

• Adult ART 2020 coverage: 81% (90% started, 90% retained); 90% of them are retained and 90% are virally suppressed

• Adult ART 2030 coverage: 90% (95% started, 95% retained); 95% of them are virally suppressed

• Eligibility for treatment expands to all PLHIV by 2018

Effectiveness: 62%

Calculation (for 2020):

On ART: 81%

Not on ART: 19%

Of those on ART percentage virally suppressed: 81%

Of those on ART percentage not virally suppressed: 19%

On ART and virally suppressed transmission reduced: 95%

On ART not virally suppressed transmission reduced: NA

Effectiveness = 1 - (proportion on ART (proportion on ART and suppressed × transmission on ART and suppressed + proportion on ART and NOT suppressed) + proportion not on ART)

Equation: 1 - (0.81 × (0.81 × 0.05 + 0.19) + 0.19) = 0.62

5. Kripke, et al. [50] (DMPPT 2.1 model)

Lesotho, Malawi, South Africa, Uganda

• "ART effect" parameter (ratio of infectiousness with ART to without ART) was used to model the level of viral suppression: base value was 0.25 (till 2015) and reduced to 0.1 (by 2020) and 0.05 (by 2030) under 90-90-90 scenario

• Adult ART 2020 coverage: 81%

• Eligibility for treatment expands to all PLHIV by 2017

Effectiveness: 73%

Calculations (for 2020):

On ART: 81%

Not on ART: 19%

On ART transmission reduced: 90%

Effectiveness = 1 - (proportion on ART × transmission on ART + proportion not on ART)

Equation: 1 - (0.81 × 0.1 + 0.19) = 0.73

6. Korenromp, et al. [51] (GOALS model)

Mozambique

• ART reduces infectivity of PLHIV by 80%, as an average effectiveness between recent studies including a 96% reduced infectivity found in a clinical trial across multiple-mainly developed, western-countries with very high adherence [7,8], a 38% reduction in a high-coverage ART program in rural South Africa [9]; 85% suppression observed in Swaziland [SHIMS 2010-12; Justman CROI 2013]

• Scenario 'current targets': ART is scaled-up from 56% to 76% of adults with CD4 < 350 in North region, from 65% to 81% in Center, and from 57% to 85% in South; additionally eligibility includes TB/HIV-co-infected adults and pregnant women (from 2012 and 2014, respectively), in all scenarios irrespective of CD4 count.

• Scenario 'Accelerated scale-up': ART is further scaled-up to 85% of eligible PLHIV with CD4 < 350 and all FSW irrespective of CD4 count

• Retention on ART, at 3 years after enrolment: 52% in current targets scenario and 70% in Accelerated scale-up scenario

Effectiveness: 20%

Calculations (for 2020):

On ART: 35% (imputed)

[85% of those < 350 CD4 cell count (i.e. 25% of PLHIV), ART for all pregnant women, female sex workers, TB/HIV]

Not on ART: 65%

Retention on ART: 70%

On ART transmission reduced: 80%

Effectiveness = 1- [(proportion of those ART × proportion on ART and retained × transmission on ART) + (1 - proportion on ART and not retained and those not on ART) × transmission not on ART]

Equation: 1 - ((0.35 × 0.7 × 0.2) + (1-0.35 × 0.7) × 1)) = 0.20

7. Walensky, et al. [52] (CEPAC model)

South Africa

• UNAIDS Target strategy: 73% suppression in 5 years from 24% current

• HIV transmission rates by disease stage and viral load: 0.16-9.03/100-person years

• Mean ART efficacy, % virologic suppression at 48 weeks: 72%

Effectiveness: 58%

Calculations (for 2020):

On ART: 90%

Not on ART: 10%

Of those on ART percentage virally suppressed: 90%

Of those on ART percentage not virally suppressed: 10%

On ART and virally suppressed transmission reduced: 72%

On ART not virally suppressed transmission reduced: NA

Effectiveness = 1 - (proportion on ART (proportion on ART and suppressed × transmission on ART and virally suppressed + proportion on ART not suppressed) + proportion not on ART)

Equation: 1- (0.90 × (0.90 × 0.28 + 0.1) + 0.1) = 0.58

8. Olney, et al. [53] (Imperial model)

Kenya

• Infectiousness of HIV-positive, on ART and virally suppressed: 0.1 (estimate)

• Proportion of individuals initiating ART who adhere to ART and achieve viral suppression: 86%

Effectiveness: 58%

Calculations (for 2020):

On ART: 75% (communication with author)

Not on ART: 25%

Of those on ART percentage virally suppressed: 86%

Of those on ART percentage not virally suppressed: 14%

On ART and virally suppressed transmission reduced: 90%

On ART not virally suppressed transmission reduced: NA

Effectiveness = 1 - (proportion of people on ART in 2020 (Proportion on ART and suppressed × transmission on ART and suppressed + proportion on ART not suppressed) + proportion not on ART)

Equation: 1 - (0.75 × (0.86 × 0.1 + 0.14) + 0.25) = 0.58

9. Hontelez, et al. [54] (STDSIM model)

10 sub-Saharan African countries (80% regional burden)

• ART reduces infectiousness of HIV by 90%

• Under 90-90-90 scenario, 81% ART coverage and 73% viral suppression among people living with HIV achieved

Effectiveness: 73%

Calculations (for 2020):

On ART: 81%

Not on ART: 19%

On ART transmission reduced: 90%

Effectiveness = 1- (proportion on ART × transmission on ART + proportion not on ART)

Equation: 1- (0.81 × 0.1 + 0.19) = 0.73

*PLHIV: People living with HIV; MSM: Men who have sex with men; FSW: Female sex workers; NA: Not available.

Note: When data are not available, we assume 0% reduction in transmission.