Sources (see cell notes for more details)

We have chosen to use a baseline rate of new HIV infections of 3 per 100 person years for our best-guess estimate. The Bridge to Scale program is operating in high-incidence counties in Kenya with high-incidence populations (adolescent girls and young women, men who have sex with men, female sex workers, and male sex workers). The WHO notes that HIV incidence rates can reach 3 per 100 person-years in these groups. Given limited information about the targeted population groups, we would guess that 3 per 100 person years is a reasonable baseline estimate of the HIV incidence rate for groups targeted by the Bridge to Scale program. We are highly uncertain about this estimate.

Note that this estimate only includes Jhpiego's budgeted costs for this program. We are uncertain exactly which elements of the program Jhpiego's budget will cover (e.g., the cost of medications, marketing, M&E, technical assistance). We would guess that Jhpiego's budget will not cover all program costs, so we consider this to be a low-end estimate.

Averting one case of HIV through PrEP may have a "multiplier effect" at the population level, since, in absence of a PrEP program, targeted individuals may not only aquire HIV themselves, but may also later spread it to others. We do not have a strong understanding of the best estimate to use for this multiplier. We have searched academic sources for estimates of a "multiplier effect" for PrEP programs, but were unable to find any estimates. Instead, as a rough approximation we use an estimate of a multiplier effect for voluntary medical male circumcision (VMMC) programs (see source and note on the following cell).

((1 - % eligible population not receiving ART in Sub-Saharan Africa (see extraction + calcs)) *1.3) [note that we arbitrarily assume higher ART coverage to account for increases in ART coverage over time and other factors]

World Health Organization – HIV/AIDS – 2015

On average, acute physical suffering and death from AIDS occurs ~10 years after infection. Accordingly, our model discounts the benefits of VMMC back 10 years. However, our guess is that significant negative psychological, social and economic impacts occur earlier – both at the time a person discovers their positive status and at the time it becomes known to others. We therefore encourage interested readers to tailor the discount to their assessment of when the negative effects of HIV would accrue.

GiveWell's 2020 Cost-effectiveness analysis - version 2

(1 - % individuals who would receive ART) * 0.5 (see survival rate at 10 years in Van der Paal et al 2007)

https://docs.google.com/spreadsheets/d/1OE3zJpnL6W2zgqA0UR6UVM_p1zAHwxixtKFQkEosoEM/edit#gid=0

We average the DALY weight for "HIV: symptomatic, pre-AIDS" (0.274) with the DALY weight for "AIDS: not receiving antiretroviral treatment" (0.582)

2020 moral weights explanation document

2020 Cost-effectiveness Analysis - version 2

Note: This CEA was created in Feb 2017 (original version here). Moral weights were updated in February 2021