HIV/AIDS Research

AHRQ sponsors Medical Care supplement on new HIV/AIDS empirical studies

The Agency for Healthcare Research and Quality recently sponsored the publication of a supplement to the journal Medical Care that features seven new empirical studies on health care for people with HIV disease. Five of the seven studies were based on data from the HIV Research Network (HIVRN). The HIVRN was established through a joint effort by AHRQ, the Substance Abuse and Mental Health Services Administration, the Health Resources and Services Administration, and the National Institutes of Health.

The studies summarized here examined data for both adults and children with HIV disease on hospitalizations, inpatient and outpatient visits, prophylaxis for opportunistic illnesses, and the impact of highly active antiretroviral therapy (HAART). A limited number of copies of the September 2005 supplement are available (AHRQ Publication No. OM06-0024) are available from the AHRQ Publications Clearinghouse.

Betz, M.E., Gebo, K.A., Barber, E., and others (2005, September). "Patterns of diagnoses in hospital admissions in a multistate cohort of HIV-positive adults in 2001." Medical Care 43(9 Suppl.), pp. III-3-III-14.

The introduction of HAART in the mid-1990s reduced morbidity, mortality, and hospitalizations among HIV-infected patients. Yet, by 2001, 5 years after the introduction of HAART, AIDS-defining illnesses (ADI) such as Pneumocystis jiroveci pneumonia (PCP) still accounted for the largest number of hospital admissions among HIV-infected patients (21.6 percent) compared with other diagnoses. The researchers collected demographic and health care data for 8,376 patients from 6 U.S. HIV care sites in 2001 and compared patients with admissions for ADI with patients admitted for other diagnoses. Among patients hospitalized at least once, 28 percent were hospitalized for an ADI (most commonly PCP and pneumonia). The most common hospitalizations were ADI (21.6 percent), gastrointestinal diseases such as pancreatitis (9.5 percent), mental illnesses (9 percent), and circulatory diseases (7.4 percent).

Rutstein, R.M., Gebo, K.A., Flynn, P.M., and others (2005, September). "Immunologic function and virologic suppression among children with perinatally acquired HIV infection on highly active antiretroviral therapy." Medical Care 43(9 Suppl.), pp. III-15-III-22.

The advent of HAART has led to a marked decrease in morbidity and mortality among HIV-infected children. However, children on HAART are less likely to achieve HIV suppression than adults on HAART, and HIV tends to progress more rapidly among children. These researchers assessed the level of HIV suppression and immune function in 263 children on HAART. Nearly 29 percent had an AIDS diagnosis. Despite receiving HAART, few HIV-infected children in this study were able to reduce their HIV load below detectable levels. However, the majority of children had near-normal CD4 counts (an indicator of good immune system functioning).

Gebo, K.A., Fleishman, J.A., Reilly, E.D., and Moore, R.D. (2005, September). "High rates of primary Mycobacterium avium complex and Pneumocystis jiroveci prophylaxis in the United States." Medical Care 43(9 Suppl.), pp. III-23-III-30.

Researchers collected demographic, clinical, and pharmacy use data on adults with HIV from 10 U.S. HIV primary care sites in the HIV Research Network who were considered patients eligible for prophylaxis against opportunistic infections (OIs) such as Pneumocystis jiroveci pneumonia (PCP) or Mycobacterium avium complex (MAC). Among eligible patients, 88 percent received PCP prophylaxis and 88 percent received MAC prophylaxis, which is considerably higher than the 65 to 80 percent for PCP and 40 percent for MAC reported in previous studies.

About 80 percent of those receiving OI prophylaxis had four or more outpatient visits during the study year (quarterly visits are recommended for HIV patients). After adjustment for site of care, men were 47 percent more likely, those with Medicare coverage 60 percent more likely, and those with four or more outpatient visits in the year over twice as likely to receive PCP prophylaxis. Having four or more outpatient visits in the year was associated with 85 percent greater likelihood of receipt of MAC prophylaxis.

Rutstein, R.M., Gebo, K.A., Siberry, G.K., and others (2005 September). "Hospital and outpatient health services utilization among HIV-infected children in care 2000-2001." Medical Care 43(9 Suppl.), pp. III-31-III-39.

Researchers in this study found lower hospitalization rates and similar outpatient care use among HIV-infected children in 2000 and 2001 compared with the pre-HAART era. Although the overall drop in children's care use may be the result of newer antiretroviral therapies, part of the difference might be a result of the general aging of the pediatric HIV-infected population, note the researchers. For example, in 1991 and 1992, 6 percent of pediatric patients were less than 1 year old with no child older than 12 years. In the current study, the age ranged from birth to 17 years and less than 7 percent were under 2 years. The researchers examined hospital and outpatient health care use among 303 HIV-infected children cared for at 4 U.S. HIV primary pediatric and specialty care sites in 2000 and 2001. During the 1-year period, 22 percent of children were hospitalized at least once. Hospitalization rates decreased significantly from 39.2 to 25.3 admissions per 100 patients. Hospitalizations were higher among children with more suppressed immune systems, those 2 years and under, and those with AIDS, but were not significantly related to receipt of HAART. Children 2 years and under, those on HAART, those with AIDS, and those with Medicaid insurance had significantly higher outpatient use.

Fleishman, J.A., Gebo, K.A., Reilly, E.D., and others (2005, September). "Hospital and outpatient health services utilization among HIV-infected adults in care 2000-2002." Medical Care 43(9 Suppl.), pp. III-40-III-52.

Some studies have suggested that HIV-related hospitalization rates may be increasing as a result of liver complications due to hepatitis C, which coinfects many patients with HIV disease, or to complications of HAART, including diabetes, cardiovascular, or cerebrovascular disease. Yet, this study of adult HIV patients from 11 HIV primary and specialty care sites found minimal change in hospital use between 2000 and 2002. The average number of admissions per person per year decreased from 0.40 in 2000 to 0.35 in 2002, a statistically insignificant difference. However, HIV hospitalization rates remained relatively high among minority or disadvantaged groups, such as intravenous drug users and Medicaid-insured patients, suggesting persistent disparities in care.

Average annual outpatient visits decreased from 6.06 to 5.66 visits per person per year. Inpatient costs per patient per month (PPPM) were estimated to be $514 in 2000, $472 in 2001, and $424 in 2002. Outpatient costs PPPM were estimated at $108 in 200l, $100 in 2001, and $101 in 2002. Patients on HAART had higher use and costs for outpatient care than those not on HAART, but receipt of HAART was not strongly related to reduced inpatient costs.

Hellinger, F.J., and Encinosa, W.E. (2005, September). "Inappropriate drug combinations among privately insured patients with HIV disease." Medical Care 43(9 Suppl.), pp. III-53-III-62.

Currently, 21 antiretroviral drugs are approved for the treatment of HIV disease, and the potential number of drug combinations available to treat the disease is overwhelming. People with HIV disease who receive inappropriate drug combinations are more likely to be hospitalized and have higher insurance claims costs than those who don't, according to a study by Agency for Healthcare Research and Quality investigators, Fred J. Hellinger, Ph.D., and William E. Encinosa, Ph.D. This study examined inappropriate drug combinations among privately insured patients with HIV disease using a database of claims information about enrollees in health benefit plans sponsored by 41 large employers. The researchers found an inappropriate drug combination in about 2 percent of the 2,110 person-years of data. Individuals who received an inappropriate drug combination were more than twice as likely as those who didn't to be hospitalized and to have higher claims costs during the year.

One half of all of the inappropriate drug combinations involved a single lipid-lowering agent (simvastatin). The patients who received protease inhibitors and simvastatin were more likely than others to suffer from muscle damage.

DeLorenze, G.N., Follansbee, S.F., Nguyen, D.P., and others (2005, September). "Medication error in the care of HIV/AIDS patients: Electronic surveillance, confirmation, and adverse events." Medical Care 43(9 Suppl.), pp. III-63-III-68.

Researchers in this study examined several categories of medication errors that occurred during treatment of 5,473 HIV/AIDS outpatients enrolled in a large California health plan. Errors included: incorrect dosing, coadministration of contraindicated medications, antiretroviral monotherapy, duplicate medication, and sound alike/look alike medication errors. Among the five error categories, positive predictive values of errors identified by the computerized pharmacy databases ranged from a high of 80 percent for coadministration of contraindicated medications to less than 1 percent for antiretroviral monotherapy. Incidence of confirmed errors was 9.8 errors per 1,000 new prescriptions dispensed for incorrect dosing, 9.51 errors per 1,000 for contraindicated medications, and <1.0 for all other error categories. Contraindicated medications was the only error category associated with adverse drug events.

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