Care for HIV infection in the US: can we do better?

Highly active antiretroviral therapy (HAART) has been tremendously successful in reducing mortality from HIV infection in the developed world and is beginning to reach needy persons in the developing world. Mortality in the US has decreased by about 75% from its peak in the mid-1990s. Survival of patients infected with HIV in the developed world is now estimated in some studies in decades rather than individual years. Potent drugs in existing classes and drugs from new classes are coming down the development pipeline. Given this success, it is tempting to believe that we have maximized care for HIV-infected individuals in the US and that we simply need to keep that stream of new drugs full for our patients who are gradually exhausting (or who have already exhausted) treatment options while we work towards a cure. That may be the case for some patients, but for most, there remains plenty of room for improvement.

For HIV care to be maximally effective, all persons with HIV infection must be diagnosed as infected and must enter and remain in care, while those persons with a clinical indication for HAART must receive it and, finally, must adhere to HAART. Failure at any one of these steps will adversely affect not only the individual's but the public's health as well.

Unfortunately, large portions of the population infected with HIV are under-treated, even in the US and other developed countries. In other words, even with no new drugs or treatment strategies, we can do far better at caring for persons infected with HIV. The US Centers for Disease Control and Prevention (CDC) estimates that 25% of persons with HIV infection are unaware of their infection. Once they become aware of their status, people reduce their risky behavior by about two-thirds, thus helping to limit transmission of the virus to others. Persons who are unaware of their status are estimated to be responsible for 50% to 70% of HIV transmission in the US. Clearly, any decrease in the proportion of persons unaware of their HIV infection could improve public health.

Further, almost half the persons who are diagnosed with HIV in the US are not diagnosed until their disease is advanced enough to adversely affect long-term prognosis. In urban hospitals throughout the country, people with previously undiagnosed HIV infection still present with and die from severe Pneumocystis pneumonia, toxoplasmosis, and cryptococcal meningitis. Recent research suggests that about 75% of patients ultimately diagnosed with advanced HIV infection have had previous encounters with the health care system, often in emergency departments, mostly without conditions that would trigger HIV testing. For these reasons and others, the CDC has released new guidelines for HIV testing that encourage widespread screening for infection and reduce the barriers to testing, while still maintaining that testing must be both voluntary and informed. These guidelines have the potential to reduce the number of persons newly infected with HIV and improve the prognosis of many who are infected. They should be carefully and conscientiously implemented.

Once they are diagnosed with HIV infection, many people delay accessing health care. A number of studies have shown that delays can range from a few months to many years. Denial, stigma, fear, lack of health insurance, perceived lack of access to health care, substance use, and psychiatric illness all contribute to this problem. Often the site of diagnosis is not an HIV clinic so a "hand-off" must occur, sometimes not only from one provider to another, but from one health care system to another. Case management can be an effective tool for smoothing the transition into HIV care, but the patient still has to be linked to HIV case management. The burden is especially high on the uninsured, who must establish and then maintain eligibility for publicly funded programs. There is little research on how to best accomplish this difficult transition.

Once in care, patients must receive and then adhere to HAART. Recent deaths of patients on the AIDS Drug Assistance Program (ADAP) waiting lists in several states tragically demonstrate that even in the US, not all persons who need access to HIV medications can get them. Patients who do get HAART must then adhere to the treatment regimens. Reduced adherence to HAART contributes to earlier viral failure and faster disease progression leading to death. While adherence in clinical trials is often excellent, adherence in routine care is generally between 50% and 80%. Researchers are just beginning to develop some effective interventions to improve adherence, but there is no "magic bullet" that will work for every patient.

Remaining in care is challenging for patients with HIV infection. Providers often struggle to comprehend why a patient fails to remain in care when doing so means that the provider can give the patient medications at low cost that will turn this otherwise fatal infection into a manageable, chronic illness. From the patient's standpoint, however, HIV infection is often only one threat of many to his or her health and welfare. The HIV-infected population is socioeconomically vulnerable, with about half the persons in care dependent on the Ryan White CARE Act or Medicaid/Medicare. Other common threats include substance use, psychiatric disease, and legal problems. A person who feels well but has unstable housing, no telephone, limited means of transportation, and a fixed, low income may have little drive to expend some of their limited resources on getting an appointment with a provider, having blood drawn for a laboratory assessment, and attending an appointment with a provider. Lapses in care are not uncommon--as any clinician can attest. Other reasons for lapses include problems navigating the health care system, logistical barriers (for example, limited clinic hours and difficulties maintaining eligibility for publicly funded services or health insurance coverage), denial, fear, and stigma.

These same factors contribute to poor adherence to HAART. Persons with poor clinic attendance generally have poor adherence to medications. However, poor adherence to HAART is not the only reason that retention in care is important. Many persons with HIV infection do not die from HIV infection, they die with HIV infection. For example, substance use and psychiatric disease can lead to traumatic or accidental deaths, hepatitis C infection can lead to liver failure, and diabetes, hypertension, obesity, and smoking can lead to early heart disease. These comorbid medical conditions require active management. Poor retention in care may result in inadequate treatment of these and other serious conditions. While the Health Resources and Services Administration (HRSA) and the CDC have sponsored some research on retention in care, there remains much work to be done and much room for improvement. Innovative models of health care delivery, case management, and chronic disease management will likely be needed to maximize retention rates.

When examining the US health care system as a whole, it is clear that we are not succeeding at assisting a large proportion of patients in navigating all the steps of HIV care. The CDC estimates that about 50% of persons with HIV infection in the US are not presently in HIV care. Some are undiagnosed, some have not yet entered care, and others have fallen out of care. Many patients on HAART will have inadequate adherence to their medications. Many in care will only sporadically engage in care and as a result, will not be adequately treated for their HIV infection and for serious comorbid conditions. While new medications to treat HIV are certainly needed, significant improvements in viral, immunologic, and clinical outcomes could be achieved from improving timely diagnosis of HIV infection, and access to and retention in care, as well as adherence to HAART. There is no time for complacency in the US as we work towards a cure for HIV infection.

Thomas P. Giordano is Assistant Professor of Medicine at Baylor College of Medicine in Houston.