Are we shifting attrition downstream in the HIV cascade?
Authors: Matthew P Fox
Journal: The Lancet HIV (2016)

As countries begin removing CD4 threshold barriers to antiretroviral therapy (ART) initiation (ie, treat all)1WHOConsolidated guidelines on the use of antiretroviral drugs for treating and preventing HIV infection recommendations for a public health approach. 2nd edn. World Health Organization, Geneva, Switzerland2016Google Scholar for those with HIV, questions remain as to how countries will implement this strategy. Because numerous reviews have shown that retention in all stages of the HIV care cascade is less than optimal,2Fox MP Rosen S Retention of adult patients on antiretroviral therapy in low- and middle-income countries: systematic review and meta-analysis 2008–2013.J Acquir Immune Defic Syndr. 2015; 69: 98-108Crossref PubMed Scopus (220) Google Scholar, 3Fox MP Rosen S Systematic review of retention of pediatric patients on HIV treatment in low and middle-income countries 2008–2013.AIDS. 2015; 29: 493-502Crossref PubMed Scopus (53) Google Scholar, 4Rosen S Fox MP Retention in HIV care between testing and treatment in sub-Saharan Africa: a systematic review.PLoS Med. 2011; 8: e1001056Crossref PubMed Scopus (597) Google Scholar, 5Kranzer K Govindasamy D Ford N Johnston V Lawn SD Quantifying and addressing losses along the continuum of care for people living with HIV infection in sub-Saharan Africa: a systematic review.J Int AIDS Soc. 2012; 15: 17383Crossref PubMed Scopus (235) Google Scholar one important question is whether changing ART eligibility criteria will, or should be, accompanied by interventions to improve retention within the HIV care cascade. In The Lancet HIV, Jack Olney and colleagues6Olney JJ Braitstein P Eaton JW et al.Evaluating strategies to improve HIV care outcomes in Kenya: a modelling study.Lancet HIV. 2016; (published online Oct 19.)http://dx.doi.org/10.1016/S2352-3018(16)30120-5PubMed Google Scholar assessed this topic with intriguing results. With an individual-level microsimulation populated with data from Kenya, they found that a universal test-and-treat approach alone (including seeking out those who are positive for HIV), although more effective overall at reducing mortality, might not be as cost-effective as a combination of interventions targeted at improving the care cascade (including improved linkage, point-of-care CD4 testing, and outreach). This finding is because the universal test-and-treat approach gets more patients into the health care cascade but it does not prevent leaks downstream in the cascade. This outcome begs the question, how much do we really know about interventions to improve the care cascade to inform mathematical models like this? We still do not know whether the effects of interventions designed to link and retain patients in HIV care are long-lasting, or if for some patients the interventions simply put off an inevitable loss from care. Olney and colleagues found that the package of interventions most effective at reducing mortality are services designed to improve earlier stages of the cascade. But to improve the cascade overall, we must recognise that the barriers to entering care might not be the same as the barriers to initiating ART among those linked, which might not be the same as the barriers to remaining on ART long term. Singular approaches that target either a limited set of barriers or a single stage of the cascade are unlikely to maximise reductions in mortality and HIV transmission, and might be shifting attrition to later stages in the care cascade. This effect is problematic for mathematical models because assumptions often need to be made that people who are prevented from dropping out of care by an intervention targeted at one stage are similar to those who already remained in care without intervention. This assumption seems unlikely to be the case as those prevented from dropping out of care early might be more likely to drop out later. If interventions are evaluated on the basis of short-term outcomes or focus on only a single stage in the care cascade (eg, linkage to care but not ART initiation), results will probably appear overly optimistic if these interventions simply shift losses from earlier in the cascade to later stages not studied.7Fox MP Rosen S Geldsetzer P Bärnighausen T Negussie EK Beanland R Interventions to improve the rate or timing of initiation of antiretroviral therapy for HIV in sub-Saharan Africa: meta-analyses of effectiveness.J Int AIDS Soc. 2016; 19: 20888Crossref PubMed Scopus (49) Google Scholar Therefore, long-term follow up of multifaceted approaches targeting multiple stages of the cascade are needed. As we enter this new treat-all phase, we also have a chance to collect data to inform practice in the future. Published research on the HIV care cascade and interventions to improve it has several limitations, including absence of standardised outcome definitions,8Fox MP Larson B Rosen S Defining retention and attrition in pre-antiretroviral HIV care: proposals based on experience in Africa.Trop Med Int Health. 2012; 17: 1235-1244Crossref PubMed Scopus (45) Google Scholar failure to account for so-called silent transfers,9Geng EH Glidden DV Bwana MB et al.Retention in care and connection to care among HIV-infected patients on antiretroviral therapy in Africa: estimation via a sampling-based approach.PLoS One. 2011; 6: e21797Crossref PubMed Scopus (73) Google Scholar and a failure to track patients across multiple stages of care long term. Although numerous strategies have been proposed to improve retention of patients, evaluations of these interventions are scarce.10Govindasamy D Meghij J Negussi EK Baggaley RC Ford N Kranzer K Interventions to improve or facilitate linkage to or retention in pre-ART (HIV) care and initiation of ART in low- and middle-income settings: a systematic review.J Int AIDS Soc. 2014; 17: 19032Crossref PubMed Scopus (191) Google Scholar, 11MacPherson P Munthali C Ferguson J et al.Service delivery interventions to improve adolescents' linkage, retention and adherence to antiretroviral therapy and HIV care.Trop Med Int Heal. 2015; 20: 1015-1032Crossref PubMed Scopus (117) Google Scholar, 12Uyei J Coetzee D Macinko J Guttmacher S Integrated delivery of HIV and tuberculosis services in sub-Saharan Africa: a systematic review.Lancet Infect Dis. 2011; 11: 855-867Summary Full Text Full Text PDF PubMed Scopus (59) Google Scholar, 13Wynberg E Cooke G Shroufi A Reid S Ford N Impact of point-of-care CD4 testing on linkage to HIV care: a systematic review.J Int AIDS Soc. 2014; 17: 18809Crossref PubMed Scopus (91) Google Scholar More data are needed, particularly under routine conditions, but so are more robust evaluations. Focusing on standard definitions, retention across multiple stages of care, and standardised follow-up periods will allow for improved decision making in the future. Olney and colleagues noted that, “If greater synergy among interventions can be achieved than our model simulations, greater benefits might be realised at lower costs.”6Olney JJ Braitstein P Eaton JW et al.Evaluating strategies to improve HIV care outcomes in Kenya: a modelling study.Lancet HIV. 2016; (published online Oct 19.)http://dx.doi.org/10.1016/S2352-3018(16)30120-5PubMed Google Scholar Although true, the opposite might also be true. If patients who are helped by an intervention in one stage of the cascade are then more likely to drop out of care at a later stage, overall outcomes could be worse than predicted. Identification of new effective approaches to improve retention throughout the care cascade and work to rigorously measure the combined benefits of multifaceted approaches over the long term should be done to ensure that attrition is reduced, not simply delayed. I declare no competing interests. Evaluating strategies to improve HIV care outcomes in Kenya: a modelling studyWhen resources are limited, combinations of interventions to improve care should be prioritised over high-cost strategies such as universal test-and-treat strategy, especially if this is not accompanied by improvements to the care cascade. International guidance on ART should reflect alternative routes to programme strengthening and encourage country programmes to evaluate the costs and population-health impact in addition to the clinical benefits of immediate initiation. Full-Text PDF Open Access