Table 2 Key model parameters
From: Investigating zero transmission of HIV in the MSM population: a UK modelling case study
Policy Aim | Key Parameter | Description of parameter |
|---|---|---|
Decreasing the size of the susceptible population | Annual probability for an HIV-negative individual to start PrEP | Allows the number of individuals taking PrEP to be adjusted through changing the rate of uptake |
Reducing the length of time over which MSMLWH can transmit the virus | Proportion of MSMLWH diagnosed within three months of transmission | Models the early diagnosis of MSMLWH and allows individuals to move to ‘on treatment’ health states more quickly |
Annual probability of screening HIV-negative individuals and undiagnosed MSMLWH | Represents the proportion of MSM tested for HIV every year | |
Proportion of MSMLWH starting treatment within six months of diagnosis | Represents the proportion of diagnosed MSMLWH starting treatment within six months of receiving a diagnosis | |
Proportion of MSMLWH starting treatment within three months of diagnosis | Models the ‘Immediate ART’ policy in which individuals initiate ART within 90 days of diagnosis [10] | |
Proportion of MSMLWH using ART who are virologically suppressed | Defines the proportion of individuals who achieve virologic suppression while on treatment. It is assumed that ART is 100% effective and MSMLWH who are virologically suppressed are unable to transmit HIV to others (also known as U = U). This parameter is henceforward referred to as TasP |