WASHINGTON — More HIV patients are living long enough to die of non-HIV causes, and clinicians who treat these patients will need to juggle the management of HIV with the management of other medical conditions, said Dr. Amy C. Justice at the Ryan White CARE Act meeting on HIV treatment.
“It's not appropriate to take guidelines for patients who don't have HIV and blindly apply them to people with a very different prognosis,” said Dr. Justice, of the West Haven Veteran's Affairs Medical Center and Yale University, both in New Haven, Conn.
Adapting guidelines intended for general populations to HIV patients remains a challenge, Dr. Justice acknowledged. Patients with HIV are a special population that is more likely to drink heavily, smoke, have viral hepatitis, and have some type of mental illness. In addition, many HIV patients are poor and have few resources, she said.
However, the same demographic factors—including age, race, and sex—that influence the development of comorbidities in the general population also apply to HIV patients.
The bottom line is that clinicians need to decide which comorbidities are worth worrying about in the HIV-positive population. Dr. Justice advises clinicians to consider three questions:
▸ What is the prognosis? Will the HIV patient live long enough to benefit from treatment for a comorbid condition?
▸ What is the impact on the patient and his or her community? Is the condition prevalent and harmful?
▸ What is the benefit of intervention? Even if a condition is prevalent and harmful (such as diabetes), treating it may not improve the patient's outcome.
Although antiviral therapy has extended the life expectancy of HIV patients, data have shown that the survival rate drops with age. Based on census data and a computer simulation developed at Yale University, more HIV patients are likely to die from non-HIV causes than from HIV in the future.
“The older you are, the more likely you are to die a non-AIDS-related death because you have increasing rates of comorbid illness as you get older,” Dr. Justice explained. If the mean age at HIV diagnosis remains 38 years, the mean age at death will likely approach 58 years before long, she added.
Hepatitis C, hypertension, diabetes, and chronic obstructive pulmonary disease are the most common comorbidities among HIV patients, with prevalences of 34%, 32%, 13%, and 12%, respectively, according to data from the Veterans Aging Cohort 3 Site Study (VACS3).
The study, conducted by Dr. Justice and her colleagues, involved a review of the records of more than 800 HIV-positive patients seen at veterans' hospitals between June 1999 and July 2000 (Med. Care 2006;44:S52–60).
“Theoretically, HIV itself may alter the association between the condition and the outcome,” Dr. Justice said. For example, HIV may make diabetes worse. The stress of fighting the virus may affect the body's blood glucose levels, in the same way that active bacterial infections do. Comorbidities also have an impact on survival rates in HIV patients through their effects on antiviral therapy adherence, she said.
For example, substance use may not only reduce adherence to HIV treatment, but it may also exacerbate comorbid conditions.
Alcohol is the substance most commonly used by HIV patients, Dr. Justice said. Data from multiple studies have shown that 60%-75% of patients with HIV infection drink alcohol, 40%–50% use tobacco, and 30% use other drugs such as marijuana, cocaine, and heroin.
“The level of alcohol use that may be harmful in HIV patients may be substantially lower than the level that is harmful in non-HIV patients,” Dr. Justice noted. Alcohol use by HIV patients makes the treatment of hepatitis C and other illnesses more difficult. “And it certainly increases the possibility of risky sex and poor adherence to medication,” she said.
Also, the detrimental effects of smoking may be exacerbated in HIV patients; studies suggest that HIV patients who smoke are at increased risk for emphysema, lung cancer, pneumonia, heart disease, and stroke. Additional data from the VACS study (J. Gen. Intern. Med. 2005;20:1142–5) indicated that mortality in HIV patients was more than twice as high among current smokers as in patients who had never smoked (5.4 vs. 2.5 deaths per 100 person-years).
One way to apply primary care guidelines to HIV patients is to consider the “payoff time,” Dr. Justice said. The payoff time is the estimated number of years of a patient's life during which the benefits of treating a comorbid condition outweigh the short-term harms.
Thus the value of screening procedures such as colonoscopy depends on the life expectancy related to a comorbid disease as well as HIV. For example, if a 50-year-old HIV-positive man is likely to die from HIV before treatment for colon cancer, if found, would reduce his risk of death from colon cancer, it may not be worth putting him through the discomfort and risk of a colonoscopy, Dr. Justice suggested.