HIV/AIDS Research

Course of HIV infection not related to sex, race, drug use, or socioeconomic status

How quickly persons infected with the human immunodeficiency virus (HIV) progress to full-blown AIDS (acquired immunodeficiency syndrome) and how long they survive are not related to sex, race, injection drug use, or socioeconomic status. Rather, HIV disease progression depends on CD4 cell count, receipt of antiretroviral therapy, and age, according to a study supported by the Agency for Health Care Policy and Research (HS07809).

The study showed that HIV-infected persons were twice as likely to progress to AIDS or die from their infection if they had a low CD4 cell count (201 to 350 cells compared with a normal cell count of about 1,000) and were symptomatic at study enrollment. They had nearly twice the risk (1.7) if they had received antiretroviral therapy prior to study enrollment (when the 1-2 year survival benefit of the therapy would already be partially exhausted), and an increased risk of 2 percentage points per year of age. These results provide strong evidence that the faster disease progression and shorter survival observed among women and blacks, for example, are likely the result of inadequate medical care rather than biologic differences among groups in the natural history of HIV infection, explains Richard E. Chaisson, M.D., of Johns Hopkins University School of Medicine, who led the study.

The researchers measured disease progression and survival in a group of 1,372 HIV-seropositive patients treated at a single urban center and followed for a median of 1.6 years. They found that CD4 cell count was the most important predictor of survival. There were no significant differences in survival between men and women, blacks and whites, drug users and non-drug users, or patients with different median annual incomes. Use of prophylaxis against Pneumocystis carinii pneumonia and zidovudine (ZDV) use after study enrollment (when survival benefits can be fully reaped) were associated with a significantly decreased risk of death.

Details are in "Race, sex, drug use, and progression of human immunodeficiency virus disease," by Dr. Chaisson, Jeanne C. Keruly, B.S.N., and Richard D. Moore, M.D., M.Sc., in the September 21, 1995 New England Journal of Medicine 333(12), pp. 751-756.

Researchers examine health care use and outcomes among HIV-infected women

AIDS (acquired immunodeficiency syndrome), the end stage of infection with the human immunodeficiency virus (HIV), is increasing among women at an alarming rate. By the end of June 1995, more than 68,000 cases of AIDS among women had been reported to the Centers for Disease Control and Prevention. Cases of AIDS in women have been reported in every State, and AIDS is now the leading cause of death among black women 25 to 44 years of age in New York State and New Jersey.

Despite the growing number of women infected with HIV, knowledge of their use of health care resources and methods of financing their care is surprisingly limited. In a recent study, investigators in the Center for Delivery Systems Research, Agency for Health Care Policy and Research, compared inpatient mortality and resource use for hospitalizations of women infected with HIV with those of HIV-infected males and a random sample of non-HIV-infected females from the same time period (October 1, 1986 through December 31, 1987). Data for this analysis were obtained from the large sample of hospitals participating in the Hospital Cost and Utilization Project, 1980-87 (HCUP-2).

Few differences in resource use and outcomes were found between HIV-infected women and men. However, the expected source of payment for inpatient stays differed significantly by sex, with inpatient stays of HIV-infected men more often indicating some form of private insurance, and inpatient care for HIV-infected women disproportionately financed through public sources.

Differences in resource use and outcomes between HIV-infected women and a random sample of discharges of non-HIV-infected women were striking. HIV-infected women had longer average lengths of stay and higher total hospital charges. Among women hospitalized for deliveries, the average length of stay, total charges, and charges per day were significantly higher for HIV-positive women than for women in the random sample.

Inpatient care for PCP varies according to insurance status and hospital characteristics

Racial factors do not appear to be an important determinant of the intensity of diagnostic or therapeutic care among patients who are hospitalized with Pneumocystis carinii pneumonia (PCP). Rather, variations in care for human immunodeficiency virus (HIV)-related PCP are largely due to differences in patients' health insurance and the characteristics of the admitting hospital, according to a study supported in part by the Agency for Health Care Policy and Research (HS06494 and HS07846) and the Department of Veterans Affairs (VA). This study is the first to evaluate variations in care along racial lines for persons with PCP.

The research team, led by Charles L. Bennett, M.D., of Northwestern University and the Lakeside VA Medical Center, and Susan E. Cohn, M.D., M.P.H., of Rochester University, reviewed the charts of 627 VA patients and 1,547 non-VA patients with suspected or confirmed PCP, who were hospitalized from 1987 to 1990. At VA hospitals, where financial barriers to care are minimal, in-hospital mortality rates, use and timing of bronchoscopy (used to distinguish PCP from other respiratory problems such as tuberculosis), and receipt of timely anti-PCP medications were not significantly different for white, black, and Hispanic patients with PCP. Among non-VA patients, black and Hispanic patients were more likely to die in the hospital and less likely to undergo a diagnostic bronchoscopy in the first 2 days of hospitalization.

These racial differences in mortality and use of bronchoscopy were almost entirely accounted for by differences in health insurance and hospital characteristics. Having Medicaid insurance and receiving care at county and State hospitals were the major factors associated with patients not undergoing a bronchoscopy.

The investigators point out that physicians receive lower reimbursement for bronchoscopies under Medicaid than under private insurance, raising the possibility that quality of care is sensitive to level of physician payments. They add the caution, however, that the possibility that Medicaid patients choose not to have the procedures cannot be excluded. Further, they note that national policies which lead to more uniform health insurance programs are needed for persons with HIV and AIDS (acquired immunodeficiency syndrome).

Details are in "Racial differences in care among hospitalized patients with Pneumocystis carinii pneumonia in Chicago, New York, Los Angeles, Miami, and Raleigh-Durham," by Drs. Bennett and Cohn, Ronnie D. Horner, Ph.D., and others, in the August 7/21, 1995 issue of the Archives of Internal Medicine 155, pp. 1586-1592.

Publicly insured, HIV-infected patients are much less likely to undergo bronchoscopy to confirm PCP

A new study shows that publicly insured patients infected with the human immunodeficiency virus (HIV) were only half as likely to receive bronchoscopies to confirm diagnosis of Pneumocystis carinii pneumonia (PCP) as their privately insured counterparts. On the other hand, health insurance status did not affect the likelihood of these patients being offered antiretroviral therapy or of receiving aerosolized pentamidine to prevent PCP in the 6 months prior to their first PCP episode.

PCP, which is the most common HIV-related infection, often signals the onset of acquired immunodeficiency syndrome (AIDS). As such, it sometimes results in eligibility for Social Security disability and Medicaid benefits. Early diagnosis of PCP by bronchoscopy could mean the difference between a short-lived, mild disease and a fatal one, according to the researchers, who were supported in part by the Agency for Health Care Policy and Research (HS06211).

Using administrative discharge records and outpatient databases, the researchers studied 450 HIV-infected patients, mostly young, white, homosexual men, who experienced their first episode of PCP at a large California medical facility. After adjusting for differences in patient race, age, HIV severity, and mode of HIV transmission (for example, homosexual liaison or injection drug use), the researchers found that patients with public insurance were half as likely as privately insured patients to receive bronchoscopy. The reasons for this difference are unclear, according to the researchers, who note that insurers' requirements for laboratory confirmation of PCP may differ, a physician may decide to treat patients for PCP based on symptoms alone without laboratory confirmation, and some patients may refuse bronchoscopy.

Details are in "Health insurance and utilization in Pneumocystis carinii pneumonia," by Sana Loue, J.D., Ph.D., Donald J. Slymen, Ph.D., Hal Morgenstern, Ph.D., and Christopher Whalen, M.D., M.S., in the Journal of General Internal Medicine 10, pp. 461-463, 1995.

Recent studies question readiness of primary care physicians to care for HIV-infected patients

Primary care physicians are providing care for a growing number of persons infected with the human immunodeficiency virus (HIV), yet in some instances, this care may be inadequate, according to two recent studies supported by the Agency for Health Care Policy and Research (HS06454). This is unfortunate, since early primary care interventions have the potential to enhance patients' quality of life and minimize or prevent HIV-related complications such as Pneumocystis carinii pneumonia (PCP) and tuberculosis (TB), explains Paul G. Ramsey, M.D., of the University of Washington.

In the first study, a standardized patient (SP) was trained to portray a person diagnosed with HIV infection but not yet symptomatic who is seeking a primary care physician. The researchers evaluated 121 primary care physicians' abilities to assess these SPs. Only a minority of physicians recommended standard primary care screening tests and vaccinations for HIV-infected persons, including viral hepatitis screening (35 percent), syphilis serologic testing (32 percent), and pneumococcal vaccination (23 percent). Although most physicians (87 percent) indicated they would obtain CD4 cell counts (a marker of HIV disease progression), only 50 percent indicated they would start therapy to prevent PCP, a potentially life-threatening HIV-related infection. Only 53 percent of physicians recommended isoniazid therapy to prevent the development of active TB infection in patients with documented positive TB tests. Performance on each of these tasks improved with physician HIV experience. Since these studies were carried out in 1992, it is likely that many primary care physicians now have additional experience in caring for HIV patients.

In the second study, 134 primary care physicians saw an SP with an unidentified HIV infection and classic PCP symptoms, such as frequent cough and dizziness on exertion, and chest radiograph and arterial blood gas results indicating PCP. Early diagnosis and treatment can make a critical difference between PCP being a mild and relatively brief illness and one resulting in respiratory failure and death. Yet the results showed significant delay in PCP diagnosis and treatment. About 77 percent of the physicians included PCP in their differential diagnoses, and 71 percent identified the SP's HIV risk. Yet only 47 percent of physicians ordered a diagnostic test for PCP, only 12 percent prescribed an adequate dose of trimethoprim-sulfamethoxazole to treat PCP, and just 6 percent initiated adjunctive prednisone therapy, even though prednisone was indicated by the blood gas result.

For more details, see "Physicians' ability to provide initial primary care to an HIV-infected patient," by J. Randall Curtis, M.D., M.P.H., Douglas S. Paauw, M.D., Marjorie D. Wenrich, M.P.H., and others, in the August 7/21, 1995, issue of the Archives of Internal Medicine 155, pp. 1613-1618, and "Ability of primary care physicians to diagnose and manage Pneumocystis carinii pneumonia," by the same authors, in the Journal of General Internal Medicine 10, pp. 395-399, 1995.

In rating doctors, teens express special concerns about HIV transmission and confidentiality

Good infection control procedures, competency, respect for confidentiality, and good interpersonal skills, such as honesty and the ability to relate to teenagers, top the list of physician qualities teenagers value, according to a recent study. In fact, when asked to complete a questionnaire, Philadelphia 9th graders listed four of the top ten desirable physician characteristics as pertinent to infection control: physician hand washing, use of clean instruments, physician and site cleanliness, and physician seronegativity for the human immunodeficiency virus (HIV).

Concerns about infection control stemmed primarily from the adolescents' fears about becoming infected with HIV from the health care provider, an occurrence whose rarity was probably masked by the intense media coverage surrounding the case of a young woman who became HIV-infected through her dentist. These fears apparently overshadowed all other HIV education efforts in Philadelphia at the time, explains Gail B. Slap, M.D., M.S., of the University of Pennsylvania's School of Medicine, whose research was supported in part by the Agency for Health Care Policy and Research (HS07876).

Dr. Slap and her colleagues used a questionnaire to ask 6,821 Philadelphia 9th graders about characteristics of health care providers and sites that affect their decision to seek health care. The questionnaire was based on focus groups where teenagers generated a prioritized list, rather than on investigators' concepts of what would be important to teens. Six of the top items identified by teens pertained to providers' interpersonal characteristics. Specific health care site, services, or outreach programs were less important. The researchers conclude that health care providers should wash their hands in front of adolescents to allay fears of disease transmission, educate teens about their right to confidential health care, and explain how to gain access to needed care.

For more details, see "Adolescents' perceptions of factors affecting their decisions to seek health care," by Kenneth R. Ginsburg, M.D., M.S.Ed., Dr. Slap, Avital Cnaan, Ph.D., and others, in the Journal of the American Medical Association 273(24), pp. 1913-1918, 1995.

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