Chapter 4 - Other Diseases and Conditions

4.1 Other Diseases and Conditions in Veterans with HIV/AIDS

Concurrent health issues, or co-morbid conditions, can add to the complex health needs of Veterans with HIV/AIDS. PHSHG routinely reports rates of co-morbid conditions in HIV infected Veterans in VHA care both for those who have ever had the co-morbid condition and those who have a new diagnosis of the co-morbid condition in the year. Understanding the number of existing and new cases of various co-morbid conditions is important to administrators preparing workload and budget projections and to providers who must assess how these conditions affect the management of HIV disease. For example, the level of healthcare utilization for an otherwise healthy Veteran with HIV infection may be very different than for a Veteran with depression, diabetes, and hypertension as well as HIV.

In 2008, several co-morbid conditions requiring chronic medical management were present in approximately one-fifth or more of the HIV population in care at VHA: depression 51%, hypertension 49%, dyslipidemias 43%, anemia 28%, neuroses or anxiety disorders 28%, hepatitis C infection 29%, esophageal disease 22%, and diabetes 19% (Table 3). Other important clinical conditions affecting HIV care included post-traumatic stress disorder 14%, chronic obstructive pulmonary disease (COPD) 12%, hepatitis B infection 12%, ischemic heart disease 11% and chronic renal failure 8%. The prevalence of chronic hepatitis B and C in HIV infected Veterans in care in 2008 is discussed in more detail in Chapter 6 (Sections 6.4 and 6.5, respectively). Substance use is quite prevalent in the HIV infected Veteran population with 34% reporting a history of alcohol abuse and 31% with a history of illicit drug use. In 2008, 17% of HIV infected Veterans had a recent hard drug use diagnosis including use of amphetamines, cocaine, or opioids.

Some of these co-morbid conditions highlight the need for preventative care and close monitoring in this population. Several of these conditions can be exacerbated or caused by long term antiretroviral use and HIV disease itself. That may be the case for the 2.9% of HIV infected Veterans first diagnosed with anemia in 2008, 3.4% first diagnosed with hyperlipidemia, and 1.8% first diagnosed with acute or chronic renal failure.

A more complete list of the rates of both new and historical diagnoses of selected conditions for Veterans with HIV/AIDS in VHA care in 2008 can be found in Table 3.

4.2 Conditions Associated with Severe Immune Suppression

In 1993, the Centers for Disease Control and Prevention (CDC) updated its list of AIDS defining infections, conditions, and cancers.1 This categorical system classifies persons with HIV infection as having AIDS based on either diagnosis of an AIDS defining condition or severe immune suppression defined by CD4+ lymphocyte count < 200 cells/mm³ or CD4 percentage < 14%. VHA does not have an internal system for reporting an AIDS diagnosis but rather uses information on diagnoses from inpatient and outpatient care to estimate rates ofAIDS diagnoses. This approach limits the ability to assess clinical AIDS diagnosis where chronic infection (e.g., chronic intestinal, isosporiasis) or recurrence within a specific time period (e.g., recurrent pneumonia) is required to diagnose AIDS. However, VHA can still assess the majority of the conditions associated with an AIDS diagnosis. Using laboratory data, VHA can measure lowest ever VHA values for CD4+ lymphocyte count and percentage to identify an immunologic AIDS diagnosis.

Consistent with trends across the United States, significantly fewer HIV infected Veterans have been diagnosed with AIDS defining conditions in the past few years as compared to the early to mid 1990s.2 In 2008, 1.2% of the HIV infected Veteran population in care was diagnosed for with an AIDS defining condition (Table 4). The change in the proportion of Veterans who had a diagnosis of Pneumocystis jiroveci pneumonia (formerly PCP) dropped from 1.7 % to 1.2 % between 2004 and 2008 representing a 30% decrease. The decreased incidence in conditions associated with severe immune suppression observed over the past few years highlights the effectiveness of current antiretroviral therapy. Table 4 provides a list of those AIDS defining conditions reported in the target year in at least 0.5% of the population in care in 1999, 2004, or 2008.

Attributable, in part, to the large proportion of HIV infected Veterans receiving antiretroviral therapy, rates of these conditions having ever been diagnosed in the VHA for HIV infected Veterans currently in care have remained consistently low. For instance, only 8.3% of HIV infected Veterans in care in 2008 have ever been diagnosed at the VHA with Pneumocystis jiroveci pneumonia, 5% with invasive candidiasis, and 4% with tuberculosis (Table 5). These low rates are consistent with the relatively low rates of severe immunologic suppression as measured by CD4+ lymphocyte counts seen in Veterans. Fewer than 10% of the HIV infected Veterans in VHA care during 2008 have all CD4+ lymphocyte counts less than 200 cells/mm³ compared to 19% in 2002, and only 2% are severely immunosuppressed with a CD4+ lymphoctye count less than 50 cells/mm³ as compared to 7% in 2002.

A more complete list of the rates of these AIDS defining conditions diagnosed in 2008 and diagnosed ever for HIV positive Veterans in care in 2008 can be found in Table 5.

Methods

1. Diagnosis. For the co-morbid condition and the conditions of severe immune suppression analysis, a Veteran is counted as having a condition if he or she had at least one diagnosis (ICD-9) from an admission (in any rank), one problem list entry or two outpatient encounters occurring on separate dates. All codes associated with a hospitalization have the discharge date as the official date of diagnosis. For more information, contact the Public Health Strategic Healthcare Group, Center for Quality Management. In the case of outpatient coding, if the two dates span different years, then the condition is recorded as first ever in the year of the first code.

References

1. Castro, KG, Ward JW, Slutsker L, Buehler JW, Jaffe HW, and Berkelman RL. 1993 Revised Classification System for HIV Infection and Expanded Surveillance Case Definition for AIDS Among Adolescents and Adults. 1992. MMWR December 18, 1992 (RR17). Available at http://www.cdc.gov/mmwr/preview/mmwrhtml/00018871.htm
2. Detels R, Munoz A, McFarlane G, Kingsley LA, et al. Effectiveness of potent antiretroviral therapy on time to AIDS and death in men with known HIV infection duration: Multicenter AIDS Cohort Study Investigators. JAMA 1998;280:1497-503. Available at http://www.ncbi.nlm.nih.gov/pubmed/9809730