The comparative consensus modelling approach used by Eaton a
The comparative consensus modelling approach used by Eaton and colleagues is now used frequently to justify the implementation of particular HIV interventions. However, this approach produces meaningful results only if the comparison is based on valid models. Most comparative consensus studies (including that by Eaton and colleagues) have not checked for model validity.
We checked the validity of the seven South African models that Eaton and colleagues used by reproducing some of their numerical simulations (). A valid model should accurately reflect the current state of the epidemic. Notably, we show that not all of the South African models agree on the present state of the epidemic; consequently, they cannot all be valid. Two models estimate that, at present, the epidemic (ie, incidence) is fairly stable, three that it is gradually decreasing, and two that it is rapidly decreasing (). One can only have confidence in the results from a comparative analysis if it is based on valid models. Only then can a comparative consensus approach be useful to guide health policy.
We declare that we have no competing interests. We acknowledge the financial support of the (grant ).
At the end of 2012, 9·7 million people accessed antiretroviral therapy (ART) in resource-limited settings. Scale-up of ART in the past decade is estimated to have averted more than 4 million deaths. Nevertheless, an additional 16 million people are eligible for treatment under the new WHO guidelines but are yet to receive it, most of whom are in sub-Saharan Africa; all HIV positive individuals will eventually need ART. Inevitably these guidelines will affect societies in high-prevalence settings, where up to a third of the adult population will have to change their lifestyle to adhere to lifelong care and treatment. Increasing evidence shows the potential for ubiquitin activating enzyme participation to reinforce the continuum along the care pathway. First, uptake of HIV testing can increase rapidly through application of home-based and community-based HIV testing strategies. Moreover, new technologies such as self-testing with rapid oral tests offer great potential for self-management and community participation. Second, new simple technologies such as point-of-care CD4 cell tests favour community participation, and result in a reduction of the time to eligibility assessment. Another strategy that has been proposed, but not yet fully evaluated, is for community health workers (CHWs) or trained expert patients to initiate ART for clinically stable and eligible patients within their community. Such a demedicalised approach would not have been possible to contemplate only a few years ago when most patients presented late, with multiple comorbidities, and when ART needed careful supervision. Although late presentation is a challenge, overall, people are seeking care when less sick, treatment guidelines are encouraging earlier initiation of ART, and the standard first-line ART is far less toxic and easier to administer than past drugs. Furthermore, simple screening instruments to rule out tuberculosis with simple questionnaires have been validated. Finally, several studies have shown that delivery of ART within the community is associated with sustained retention and adherence. CHWs can assure ART supply within their communities, including through home-based delivery. Other approaches to community ART include monthly refills at community pharmacies or rotation of community support group members who pick up ART for the whole group at health facilities. In Mozambique, this rotation approach resulted in more than 90% retention at 4 years, which shows that retention is greatly enhanced when people living with HIV/AIDS have an active role in the daily management of their disorder. These community-based interventions have been piloted in isolation, in different settings, but can be brought together into an overarching comprehensive HIV care model that recognises the contribution of these community-based interventions as a central part of the overall response.