Scenario definitions: impact of PrEP by adherence and functional effectiveness.

All values are proportions. Functional effectiveness is a function of the probability of transmission, the intrinsic efficacy, the adherence to PrEP, and its distribution, affecting only unprotected sex acts, which in turn are dependent on the number of partners, average condom use, and number of sex acts per partner (all values derived from iPrEx data [2]).aAdherence 1, 2, and 3 refer to the proportion of doses taken consistently by an individual. The proportion in each adherence group is the population distribution (the number of people in each adherence group). This reflects the data reported in the iPrEx study: a distribution of participants by ranges of adherence. We included a point estimate within those ranges.