Linkage From HIV Testing to Care

The HIV epidemic continues unabated in the United States. Recent data demonstrated that there have been approximately 50,000 new HIV infections each year, a number unchanged for the past decade.1 At the same time, for those with HIV infection, recent findings indicate substantial deficits in the HIV “cascade” from testing to linkage-to-care and retention to adherence to antiretroviral therapy (ART) and viral suppression.2 It is estimated that viral suppression is achieved for only 28% of those estimated to be living with HIV in the United States.3 These observations are even more troubling when considered in the context of widely heralded advances in HIV treatment and prevention. The transmission prevention benefits of ART have been noted in observational studies4,5 and most recently confirmed in a randomized controlled trial in stable serodiscordant heterosexual couples.6 The findings from observational studies with regard to early ART use for the HIV-infected population at higher CD4+ cell count have been conflicting.7–10 HIV Prevention Trials Network (HPTN) 052 showed benefit of initiation of ART at a CD4+ cell count between 350 and 550 cells/mL compared with deferred initiation at CD4+ cell count of between 200 to 250 cell/mL.6 The ongoing Strategic Timing of AntiRetroviral Treatment study is examining the question of benefits versus risks of ART at CD4+ count greater than 500 cells/mL versus deferred initiation at CD4+ count less than 350 cells/mL.11 Nonetheless, based on available information, the US Department of Health and Human Service12 and International AIDS Society-United States of America13 guidelines currently support initiation of ART in the United States, regardless of CD4+ cell count. These recent recommendations must be juxtaposed against a stark reality. In a retrospective study that included individuals in HIV care enrolled in the Medical Monitoring Project, 23% of patients in care in 2007 and 2008 had more than a 3 month delay in engagement in HIV care after a positive HIV test result.14 Other data indicate that a substantial proportion of individuals with HIV infection in the United States are identified at advanced stages of HIV disease. For example, findings from one study that examined CD4+ cell count in patients in care who had HIV diagnosed within the previous 6 months showed a median CD4+ cell count of 299 cells/mL at the time of diagnosis.15 In this issue of Sexually Transmitted Disease, Johnston et al. used Medicaid claims data from 15 states to examine the issue of linkage after a positive HIV test result to HIV care. They defined engagement in care based on claims for a CD4+ count and/or viral load measurement completed after the positive test result. The authors examined the records of more than 23 million individuals included in Medicaid data between January 2003 and May 2010 from 15 states and identified 6684 persons with an HIV positive test result who fulfilled their study eligibility criteria. They found that only 21% of these individuals were linked to care in 1 year and 26.4% in 5 years, based on claims for CD4+ count or viral load testing. In a study from New York City, of 1928 patients diagnosed as having HIV infection, 63.7% initiated HIV care within 3 months.16 In this study, nonwhites were more likely to have delayed initiation of care in contrast to the finding from the study of Johnston et al., which demonstrated the opposite. In addition, the study from New York City demonstrated that living in a high-poverty area, a possible surrogate for Medicaid eligibility, was not associated with delayed initiation of HIV care, which contradicts the findings of Johnson et al. One of the interesting findings from the study of Johnston et al. is that having any clinical indicator of HIV was associated with linkage from HIV testing to HIV care. This suggests that asymptomatic HIV-infected individuals are less likely to initiate or engage in HIV care, an issue of particular significance keeping in mind current efforts to identify individuals with earlier HIV disease. It suggests the need for extraordinary efforts to ensure that such patients are engaged in care if the benefits of ART for treatment or prevention are to be achieved.17 The use of Medicaid claims data by the authors is an innovative approach, particularly because a substantial proportion of HIV-infected individuals in care in the United States have public insurance coverage.18,19 It is important to note; however, that there are limitations to the use of Medicaid claims data in addition to those cited by the authors or, for that matter, with the use of any insurance claims data to assess use of a specific service. In one study using Medicaid claims data, it was noted that 35% of pregnant women classified as not having had an ultrasound had evidence of receiving such a procedure upon review of medical records.20 Thus, validation of claims data remains a challenge. In addition, Medicaid claims data often include only fee-for-service claims and exclude managed care data.21 Over the past decade, efforts have been ongoing to enroll HIV-infected patients in managed care Medicaid programs.22 It is unclear whether this issue may have impacted the findings of Johnston et al. The United States is in a unique position based on its robust HIV surveillance system to reach a deeper understanding of the HIV continuum cascade from HIV testing to viral suppression. The required name-based reporting of all HIV positive test results, as well as direct reporting of laboratories of all HIV-related monitoring tests such as CD4+ count, viral load, and resistance testing, offers the ability to ascertain with accuracy every step of the cascade. This system was used by Torian et al.,16 who examined linkage of patients with HIV identified in New York City. An ongoing study by the HPTN, the HPTN 065 (TLC-Plus) Study, is also using surveillance data to evaluate the feasibility and effectiveness of interventions to enhance linkage and viral suppression23 in an overall attempt to assess the feasibility of a “test and treat” approach for HIV prevention in the United States. This is a moment of great excitement in the history of the HIV epidemic. Secretary of State Clinton shared her vision of an “AIDS Free Generation” at the XIX International AIDS Conference with thousands of delegates from around the world.24 However, the path ahead will not be simple. It will require attention to many issues including those highlighted in the report of Johnston et al. in this issue. As a community of providers, researchers, and public health practitioners, we must come together to address the glaring deficits in the HIV continuum and work toward optimizing every step in that critical cascade.25