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1.  CD8+ T-Cells Count in Acute Myocardial Infarction in HIV Disease in a Predominantly Male Cohort 
BioMed Research International  2015;2015:246870.
Human Immunodeficiency Virus- (HIV-) infected persons have a higher risk for acute myocardial infarction (AMI) than HIV-uninfected persons. Earlier studies suggest that HIV viral load, CD4+ T-cell count, and antiretroviral therapy are associated with cardiovascular disease (CVD) risk. Whether CD8+ T-cell count is associated with CVD risk is not clear. We investigated the association between CD8+ T-cell count and incident AMI in a cohort of 73,398 people (of which 97.3% were men) enrolled in the U.S. Veterans Aging Cohort Study-Virtual Cohort (VACS-VC). Compared to uninfected people, HIV-infected people with high baseline CD8+ T-cell counts (>1065 cells/mm3) had increased AMI risk (adjusted HR = 1.82, P < 0.001, 95% CI: 1.46 to 2.28). There was evidence that the effect of CD8+ T-cell tertiles on AMI risk differed by CD4+ T-cell level: compared to uninfected people, HIV-infected people with CD4+ T-cell counts ≥200 cells/mm3 had increased AMI risk with high CD8+ T-cell count, while those with CD4+ T-cell counts <200 cells/mm3 had increased AMI risk with low CD8+ T-cell count. CD8+ T-cell counts may add additional AMI risk stratification information beyond that provided by CD4+ T-cell counts alone.
PMCID: PMC4320893
2.  Cancer Incidence in HIV-Infected Versus Uninfected Veterans: Comparison of Cancer Registry and ICD-9 Code Diagnoses 
Given the growing interest in the cancer burden in persons living with HIV/AIDS, we examined the validity of data sources for cancer diagnoses (cancer registry versus International Classification of Diseases, Ninth Revision [ICD-9 codes]) and compared the association between HIV status and cancer risk using each data source in the Veterans Aging Cohort Study (VACS), a prospective cohort of HIV-infected and uninfected veterans from 1996 to 2008.
We reviewed charts to confirm potential incident cancers at four VACS sites. In the entire cohort, we calculated cancer-type-specific age-, sex-, race/ethnicity-, and calendar-period-standardized incidence rates and incidence rate ratios (IRR) (HIV-infected versus uninfected). We calculated standardized incidence ratios (SIR) to compare VACS and Surveillance, Epidemiology, and End Results rates.
Compared to chart review, both Veterans Affairs Central Cancer Registry (VACCR) and ICD-9 diagnoses had approximately 90% sensitivity; however, VACCR had higher positive predictive value (96% versus 63%). There were 6,010 VACCR and 13,386 ICD-9 incident cancers among 116,072 veterans. Although ICD-9 rates tended to be double VACCR rates, most IRRs were in the same direction and of similar magnitude, regardless of data source. Using either source, all cancers combined, most viral-infection-related cancers, lung cancer, melanoma, and leukemia had significantly elevated IRRs. Using ICD-9, eight additional IRRs were significantly elevated, most likely due to false positive diagnoses. Most ICD-9 SIRs were significantly elevated and all were higher than the corresponding VACCR SIR.
ICD-9 may be used with caution for estimating IRRs, but should be avoided when estimating incidence or SIRs. Elevated cancer risk based on VACCR diagnoses among HIV-infected veterans was consistent with other studies.
PMCID: PMC4285627  PMID: 25580366
Neoplasms; Registries; International Classification of Diseases; HIV Infections
3.  Medical ICU Admission Diagnoses and Outcomes in Human Immunodeficiency Virus–Infected and Virus–Uninfected Veterans in the Combination Antiretroviral Era 
Critical care medicine  2013;41(6):1458-1467.
Human immunodeficiency virus (HIV)–infected (HIV+) patients on combination antiretroviral therapy are living longer but have increased risk for aging-associated disease which may lead to increasing critical care requirements. We compare medical ICU admission characteristics and outcomes among HIV infected and demographically similar uninfected patients (uninfected) and considered whether an index which combines routine clinical biomarkers (the Veterans Aging Cohort Study Index) predicts 30-day medical ICU mortality.
Observational data analyses (Veterans Aging Cohort Study).
Eight Veterans Affairs medical centers nationwide.
HIV infected and uninfected with a medical ICU admission between 2002 and 2010.
Measurements and Main Results
Medical ICU admission was determined using bedsection (Veterans Affairs) and revenue center codes (Medicare). For Veterans Affairs admissions, we used clinical data to calculate Veterans Aging Cohort Study Index scores and multivariable logistic regression to determine factors associated with 30-day mortality. Overall, 539 of 3,620 (15%) HIV infected and 375 of 3,639 (10%) uninfected had a medical ICU admission; 72% and 78%, respectively, were Veterans Affairs based. HIV+ patients were younger at admission (p < 0.0001). Although most HIV+ patients were on antiretroviral therapy (71%) with undetectable HIV-1 RNA (54%), compared with uninfected they were more commonly admitted with respiratory diagnoses or infections (21% vs. 12%), were more likely to require mechanical ventilation (17% vs. 9%; p = 0.001), and had a higher mortality rate (18.6% vs. 11.2%, p = 0.003). Cardiovascular diagnoses were less common among HIV infected (18% vs. 29%; p < 0.0001). In logistic regression (c-statistic 0.87), a 5-point increment in Veterans Aging Cohort Study Index was associated with an odds ratio of death of 1.22 (95% confidence interval 1.14–1.30) among HIV infected and of 1.50 (95% confidence interval 1.29–1.76) among uninfected; infection/sepsis and respiratory diagnoses were also associated with mortality.
Medical ICU admission was frequent, 30-day mortality higher, and mechanical ventilation more common in HIV infected compared with uninfected. The Veterans Aging Cohort Study Index calculated at medical ICU admission predicted 30-day mortality for HIV infected and uninfected. As more individuals age with HIV, their requirements for medical ICU care may be greater than demographically similar uninfected individuals.
PMCID: PMC4283206  PMID: 23507717
30-day mortality; comorbidity; human immunodeficiency virus; medical ICU; Veterans Aging Cohort Study Index
4.  Prehypertension, Hypertension, and the Risk of Acute Myocardial Infarction in HIV-Infected and -Uninfected Veterans 
We found increased acute myocardial infarction risk among hypertensive and prehypertensive HIV-infected veterans compared to normotensive uninfected veterans, independent of confounding comorbidities.
Background. Compared to uninfected people, human immunodeficiency virus (HIV)–infected individuals may have an increased risk of acute myocardial infarction (AMI). Currently, HIV-infected people are treated to the same blood pressure (BP) goals (<140/90 or <130/80 mm Hg) as their uninfected counterparts. Whether HIV-infected people with elevated BP have excess AMI risk compared to uninfected people is not known. This study examines whether the association between elevated BP and AMI risk differs by HIV status.
Methods. The Veterans Aging Cohort Study Virtual Cohort (VACS VC) consists of HIV-infected and -uninfected veterans matched 1:2 on age, sex, race/ethnicity, and clinical site. For this analysis, we analyzed 81 026 people with available BP data from VACS VC, who were free of cardiovascular disease at baseline. BP was the average of the 3 routine outpatient clinical measurements performed closest to baseline (first clinical visit after April 2003). BP categories used in the analyses were based on criteria of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Analyses were performed using Cox proportional hazards regression.
Results. Over 5.9 years (median), 860 incident AMIs occurred. Low/high prehypertensive and untreated/treated hypertensive HIV-infected individuals had increased AMI risk compared to uninfected, untreated normotensive individuals (hazard ratio [HR], 1.60 [95% confidence interval {CI}, 1.07–2.39]; HR, 1.81 [95% CI, 1.22–2.68]; HR, 2.57 [95% CI, 1.76–3.76]; and HR, 2.76 [95% CI, 1.90–4.02], respectively).
Conclusions. HIV, prehypertensive BP, and hypertensive BP were associated with an increased risk of AMI in a cohort of HIV-infected and -uninfected veterans. Future studies should prospectively investigate whether HIV interacts with BP to further increase AMI risk.
PMCID: PMC3864500  PMID: 24065316
blood pressure; prehypertension; HIV; myocardial infarction
5.  Hepatic Decompensation in Antiretroviral-Treated HIV/Hepatitis C-Coinfected Compared to Hepatitis C-Monoinfected Patients: A Cohort Study 
Annals of internal medicine  2014;160(6):369-379.
The incidence and determinants of hepatic decompensation have been incompletely examined among HIV/hepatitis C virus (HCV)-coinfected patients in the antiretroviral therapy (ART) era, and few studies have compared rates of outcomes to those of patients with chronic HCV alone.
To compare the incidence of hepatic decompensation between antiretroviral-treated HIV/HCV-coinfected and HCV-monoinfected patients, and evaluate factors associated with decompensation among coinfected patients on ART.
Retrospective cohort study.
Veterans Health Administration.
4,280 HIV/HCV-coinfected patients who initiated ART and 6,079 HCV-monoinfected patients receiving care between 1997 and 2010. All patients had detectable HCV RNA and were HCV treatment-naïve.
Incident hepatic decompensation, determined by diagnoses of ascites, spontaneous bacterial peritonitis, or esophageal variceal hemorrhage.
The incidence of hepatic decompensation was greater among coinfected than monoinfected patients (at 10 years: 7.4% versus 4.8%; p<0.001). Compared to HCV-monoinfected patients, antiretroviral-treated HIV/HCV-coinfected patients had a higher rate of hepatic decompensation (hazard ratio [HR] accounting for competing risks, 1.56 [95% confidence interval (CI), 1.31–1.86]). Coinfected patients who maintained HIV RNA levels <1,000 copies/mL still had higher rates of decompensation than HCV-monoinfected patients (HR, 1.44 [95% CI, 1.05–1.99]). Baseline advanced hepatic fibrosis (FIB-4 >3.25; HR, 5.45 [95% CI, 3.79–7.84]), baseline hemoglobin <10 g/dL (HR, 2.24 [CI, 1.20–4.20]), diabetes mellitus (HR, 1.88[95% CI, 1.38–2.56]), and non-black race (HR, 2.12 [95% CI, 1.65–2.72]) were each associated with higher rates of decompensation among coinfected patients on ART.
Observational study of predominantly male patients.
Despite ART, HIV/HCV-coinfected patients had higher rates of hepatic decompensation than HCV-monoinfected individuals. Rates of decompensation were higher for coinfected patients with advanced liver fibrosis, severe anemia, diabetes, and non-black race.
PMCID: PMC4254786  PMID: 24723077
hepatic decompensation; end-stage liver disease; HIV/HCV coinfection; HIV; hepatitis C
6.  Risk factors for hospitalization and medical intensive care unit (MICU) admission among HIV infected Veterans 
With improved survival of HIV-infected persons on antiretroviral therapy and growing prevalence of non-AIDS diseases, we asked whether the VACS Index, a composite measure of HIV-associated and general organ dysfunction predictive of all-cause mortality, predicts hospitalization and medical intensive care unit (MICU) admission. We also asked whether AIDS and non-AIDS conditions increased risk after accounting for VACS Index score.
We analyzed data from the Veterans Aging Cohort Study (VACS), a prospective study of HIV-infected Veterans receiving care between 2002–2008. Data were obtained from the electronic medical record, VA administrative databases and patient questionnaires, and were used to identify comorbidities and calculate baseline VACS Index scores. The primary outcome was first hospitalization within 2 years of VACS enrollment. We used multivariable Cox regression to determine risk factors associated with hospitalization and logistic regression to determine risk factors for MICU admission, given hospitalization.
1141/3410 (33.5%) patients were hospitalized within 2 years; 203/1141 (17.8%) included a MICU admission. Median VACS Index scores were 25 (no hospitalization), 34 (hospitalization only) and 51 (MICU). In adjusted analyses, a 5-point increment in VACS Index score was associated with 10% higher risk of hospitalization and MICU admission. In addition to VACS Index score, Hispanic ethnicity, current smoking, hazardous alcohol use, chronic obstructive pulmonary disease, hypertension, diabetes and prior AIDS-defining event predicted hospitalization. Among those hospitalized, VACS Index score, cardiac disease and prior cancer predicted MICU admission.
The VACS Index predicted hospitalization and MICU admission as did current smoking, hazardous alcohol use, and AIDS and certain non-AIDS diagnoses.
PMCID: PMC4182723  PMID: 23111572
HIV; hospitalization; medical intensive care unit (MICU); aging; VACS Index; comorbidity
7.  Validation of an Algorithm to Identify Antiretroviral-Naïve Status at Time of Entry into a Large, Observational Cohort of HIV-infected Patients 
Pharmacoepidemiology and drug safety  2013;22(9):10.1002/pds.3476.
Large, observational HIV cohorts play an important role in answering questions which are difficult to study in randomized trials; however, they often lack detailed information regarding previous antiretroviral treatment (ART). Knowledge of ART treatment history is important when ascertaining the long-term impact of medications, co-morbidities, or adverse reactions on HIV outcomes.
We performed a retrospective study to validate a prediction algorithm for identifying ART-naïve patients using the Veterans Aging Cohort Study’s Virtual Cohort—an observational cohort of 40,594 HIV-infected veterans nationwide. Medical records for 3070 HIV-infected patients were reviewed to determine history of combination ART treatment. An algorithm using Virtual Cohort laboratory data was used to predict ART treatment status and compared to medical record review.
Among 3070 patients’ medical records reviewed, 1223 were eligible for analysis. Of these, 990 (81%) were ART naïve at cohort entry based on medical record review. The prediction algorithm’s sensitivity was 86%, specificity 47%, positive predictive value (PPV) 87% and negative predictive value 45%, using a viral load threshold of <400 copies/ml. Sensitivity analysis revealed that PPV would be maximized by increasing the viral load threshold, whereas sensitivity would be maximized by lowering the viral load threshold.
A prediction algorithm using available laboratory data can be used to accurately identify ART-naïve patients in large, observational HIV cohorts. Use of this algorithm will allow investigators to accurately limit analyses to ART-naïve patients when studying the contribution of ART to outcomes and adverse events.
PMCID: PMC3831617  PMID: 23836591
HIV-1; Antiretroviral Therapy, Highly Active; Cohort Studies; HIV infections/epidemiology; HIV infections/drug therapy
8.  Hepatitis C virus screening practices and seropositivity among US veterans born during 1945 – 1965 
BMC Research Notes  2014;7:449.
The Centers for Disease Control and Prevention (CDC) and the United States Preventive Services Task Force (USPSTF) recently augmented risk-based hepatitis C (HCV) screening guidelines with a recommendation to perform one-time screening in all persons born during 1945 – 1965, a birth cohort known to have a higher prevalence of HCV. We sought to estimate the proportion of veterans seen at the Atlanta VA Medical Center (AVAMC) who had ever been screened for HCV infection by birth year.
We used an administrative database of all veterans seen at the AVAMC between January 1, 2011 and December 31, 2011, and a laboratory generated list of all HCV antibody tests and HCV RNA viral loads that were performed at the AVAMC to determine receipt of screening and HCV antibody positivity. Odds ratios and 95% confidence intervals were estimated using SAS version 9.2 (SAS institute, Cary, North Carolina).
HCV antibody testing had ever been performed on 48% (41,556) of the veterans seen in 2011; 10% of those tested had a positive antibody. Confirmatory viral loads were performed in 96% of those with a positive antibody screen. Those born during 1945 – 1965 were more likely to have a HCV antibody performed when compared with those born in other years (54% vs. 41%, odds ratio [OR] 1.70, 95% Confidence Interval [CI] 1.65-1.74). Among veterans ever tested for HCV antibody (n = 41,556), those born during 1945 – 1965 were 6 times more likely to have a positive HCV antibody (15% vs. 3%, OR 5.87, 95% CI 5.32-6.78), and 3 times more likely to have chronic HCV infection (76% vs. 50%, OR 3.25, 95% CI 2.65-4.00).
Nearly half of the veterans seen in 2011 at the AVAMC had ever been tested for HCV infection. When examined by birth cohort, over half of the veterans born during 1945 – 1965 had been screened for HCV and 15% of those screened had a positive HCV antibody. Our findings confirm the increased prevalence of HCV infection in persons born during 1945 – 1965 as identified in the updated CDC and USPSTF recommendations.
PMCID: PMC4105869  PMID: 25023159
Hepatitis C; Screening; Prevention & control
9.  Physiologic Frailty and Fragility Fracture in HIV-Infected Male Veterans 
Frailty, as measured by the Veterans Aging Cohort Study Index, is an important predictor of fragility fracture in the context of established fracture risk factors. Anemia and increasing age drive this association in a male veteran population.
Background. The Veterans Aging Cohort Study (VACS) Index is associated with all-cause mortality in individuals infected with human immunodeficiency virus (HIV). It is also associated with markers of inflammation and may thus reflect physiologic frailty. This analysis explores the association between physiologic frailty, as assessed by the VACS Index, and fragility fracture.
Methods. HIV-infected men from VACS were included. We identified hip, vertebral, and upper arm fractures using ICD-9-CM codes. We used Cox regression models to assess fragility fracture risk factors including the VACS Index, its components (age, hepatitis C status, FIB-4 score, estimated glomerular filtration rate, hemoglobin, HIV RNA, CD4 count), and previously identified risk factors for fragility fractures.
Results. We included 40 115 HIV-infected male Veterans. They experienced 588 first fragility fractures over 6.0 ± 3.9 years. The VACS Index score (hazard ratio [HR], 1.15; 95% confidence interval [CI], 1.11–1.19), white race (HR, 1.92; 95% CI, 1.63–2.28), body mass index (HR, 0.94; 95% CI, .92–.96), alcohol-related diagnoses (HR, 1.65; 95% CI, 1.26–2.17), cerebrovascular disease (HR, 1.95; 95% CI, 1.14–3.33), proton pump inhibitor use (HR, 1.87; 95% CI, 1.54–2.27), and protease inhibitor use (HR, 1.25; 95% CI, 1.04–1.50) were associated with fracture risk. Components of the VACS Index score most strongly associated with fracture risk were age (HR, 1.40; 95% CI, 1.27–1.54), log HIV RNA (HR, 0.91; 95% CI, .88–.94), and hemoglobin level (HR, 0.82; 95% CI, .78–.86).
Conclusions. Frailty, as measured by the VACS Index, is an important predictor of fragility fractures among HIV-infected male Veterans.
PMCID: PMC3634308  PMID: 23378285
HIV; frailty; fragility fractures; Veterans
10.  Combining Epidemiologic and Biostatistical Tools to Enhance Variable Selection in HIV Cohort Analyses 
PLoS ONE  2014;9(1):e87352.
Variable selection is an important step in building a multivariate regression model for which several methods and statistical packages are available. A comprehensive approach for variable selection in complex multivariate regression analyses within HIV cohorts is explored by utilizing both epidemiological and biostatistical procedures.
Three different methods for variable selection were illustrated in a study comparing survival time between subjects in the Department of Defense’s National History Study and the Atlanta Veterans Affairs Medical Center’s HIV Atlanta VA Cohort Study. The first two methods were stepwise selection procedures, based either on significance tests (Score test), or on information theory (Akaike Information Criterion), while the third method employed a Bayesian argument (Bayesian Model Averaging).
All three methods resulted in a similar parsimonious survival model. Three of the covariates previously used in the multivariate model were not included in the final model suggested by the three approaches. When comparing the parsimonious model to the previously published model, there was evidence of less variance in the main survival estimates.
The variable selection approaches considered in this study allowed building a model based on significance tests, on an information criterion, and on averaging models using their posterior probabilities. A parsimonious model that balanced these three approaches was found to provide a better fit than the previously reported model.
PMCID: PMC3906149  PMID: 24489902
11.  Unhealthy Alcohol and Illicit Drug Use are Associated with Decreased Quality of HIV Care 
HIV-infected patients with substance use experience suboptimal health outcomes, possibly to due to variations in care.
To assess the association between substance use and the quality of HIV care (QOC) received.
Research Design
Retrospective cohort study.
HIV-infected patients enrolled in the Veterans Aging Cohort Study.
We collected self-report substance use data and abstracted 9 HIV quality indicators (QIs) from medical records. Independent variables were unhealthy alcohol use (AUDIT-C score ≥4) and illicit drug use (self-report of stimulants, opioids, or injection drug use in past year). Main outcome was the percentage of QIs received, if eligible. We estimated associations between substance use and QOC using multivariable linear regression.
The majority of the 3,410 patients were male (97.4%) and Black (67.0%) with a mean age of 49.1 years (SD 8.8). Overall, 25.8% reported unhealthy alcohol use, 22% illicit drug use, and participants received 81.5% (SD=18.9) of QIs. The mean percentage of QIs received was lower for those with unhealthy alcohol use vs. not (59.3% vs. 70.0%, p<.001) and those using illicit drugs vs. not (57.8% vs. 70.7%, p<.001). In multivariable models, unhealthy alcohol use (adjusted β −2.74; 95% CI −4.23, −1.25) and illicit drug use (adjusted β −3.51 95% CI −4.99, −2.02) remained inversely associated with the percentage of QIs received.
Though the overall QOC for these HIV-infected Veteran patients was high, gaps persist for those with unhealthy alcohol and illicit drug use. Interventions that address substance use in HIV-infected patients may improve the QOC received.
PMCID: PMC3460799  PMID: 22820808
Alcohol; Quality of Health Care; HIV; Quality Indicators; Health Care; Opioid-Related Disorders
12.  Comorbid diabetes and the risk of progressive chronic kidney disease in HIV-infected adults: Data from the Veterans Aging Cohort Study 
Approximately 15% of HIV-infected individuals have comorbid diabetes. Studies suggest that HIV and diabetes have an additive effect on chronic kidney (CKD) progression; however, this observation may be confounded by differences in traditional CKD risk factors.
We studied a national cohort of HIV-infected and matched HIV-uninfected individuals who received care through the Veterans Healthcare Administration. Subjects were divided into four groups based on baseline HIV and diabetes status, and the rate of progression to an estimated glomerular filtration rate (eGFR) < 45ml/min/1.73m2 was compared using Cox-proportional hazards modeling to adjust for CKD risk factors.
31,072 veterans with baseline eGFR ≥ 45ml/min/1.73m2 (10,626 with HIV only, 5,088 with diabetes only, and 1,796 with both) were followed for a median of 5 years. Mean baseline eGFR was 94ml/min/1.73m2, and 7% progressed to an eGFR < 45ml/min/1.73m2. Compared to those without HIV or diabetes, the relative rate of progression was increased in individuals with diabetes only [adjusted hazard ratio (HR) 2.48; 95% confidence interval (CI) 2.19–2.80], HIV only [HR 2.80, 95% CI 2.50–3.15], and both HIV and diabetes [HR 4.47, 95% CI 3.87–5.17].
Compared to patients with only HIV or diabetes, patients with both diagnoses are at significantly increased risk of progressive CKD even after adjusting for traditional CKD risk factors. Future studies should evaluate the relative contribution of complex comorbidities and accompanying polypharmacy to the risk of CKD in HIV-infected individuals, and prospectively investigate the use of cART, glycemic control, and adjunctive therapy to delay CKD progression.
PMCID: PMC3392432  PMID: 22592587
non-AIDS complications; HIV; chronic kidney disease; diabetes; risk factors
13.  HIV Status, Burden of Comorbid Disease, and Biomarkers of Inflammation, Altered Coagulation, and Monocyte Activation 
We investigated the association between human immunodeficiency virus (HIV) and prevalence of elevated biomarkers of inflammation, altered coagulation, and monocyte activation in a cohort of HIV-infected and uninfected veterans who had a comparable burden of comorbid conditions.
Background. Biomarkers of inflammation, altered coagulation, and monocyte activation are associated with mortality and cardiovascular disease (CVD) in the general population and among human immunodeficiency virus (HIV)–infected people. We compared biomarkers for inflammation, altered coagulation, and monocyte activation between HIV-infected and uninfected people in the Veterans Aging Cohort Study (VACS).
Methods. Biomarkers of inflammation (interleukin-6 [IL-6]), altered coagulation (d-dimer), and monocyte activation (soluble CD14 [sCD14]) were measured in blood samples from 1525 HIV-infected and 843 uninfected VACS participants. Logistic regression was used to determine the association between HIV infection and prevalence of elevated (>75th percentile) biomarkers, adjusting for confounding comorbidities.
Results. HIV-infected veterans had less prevalent CVD, hypertension, diabetes, obesity, hazardous drinking, and renal disease, but more dyslipidemia, hepatitis C, and current smoking than uninfected veterans. Compared to uninfected veterans, HIV-infected veterans with HIV-1 RNA ≥500 copies/mL or CD4 count <200 cells/µL had a significantly higher prevalence of elevated IL-6 (odds ratio [OR], 1.54; 95% confidence interval [CI],1.14–2.09; OR, 2.25; 95% CI, 1.60–3.16, respectively) and d-dimer (OR, 1.97; 95% CI, 1.44–2.71, OR, 1.68; 95% CI, 1.22–2.32, respectively) after adjusting for comorbidities. HIV-infected veterans with a CD4 cell count <200 cells/µL had significantly higher prevalence of elevated sCD14 compared to uninfected veterans (OR, 2.60; 95% CI, 1.64–4.14). These associations still persisted after restricting the analysis to veterans without known confounding comorbid conditions.
Conclusions. These data suggest that ongoing HIV replication and immune depletion significantly contribute to increased prevalence of elevated biomarkers of inflammation, altered coagulation, and monocyte activation. This contribution is independent of and in addition to the substantial contribution from comorbid conditions.
PMCID: PMC3493182  PMID: 22534147
14.  Sex Disparities in Overall Burden of Disease Among HIV-Infected Individuals in the Veterans Affairs Healthcare System 
Journal of General Internal Medicine  2013;28(Suppl 2):577-582.
Whether sex disparities exist in overall burden of disease among human immunodeficiency virus (HIV)-infected individuals in the Veterans Affairs healthcare system (VA) is unknown.
To determine whether sex differences exist in overall burden of disease after 1 year of combined antiretroviral therapy (ART) among HIV-infected individuals in VA.
Retrospective cohort study.
Among patients in the Veterans Aging Cohort Study Virtual Cohort (VACS-VC), all ART-naïve HIV-infected Veterans who received VA-based HIV care between 1996 and 2009.
Overall burden of disease was measured using the VACS Index, an index that incorporates HIV (e.g. CD4 cell count) and non-HIV biomarkers (e.g. hemoglobin) and is highly predictive of all-cause mortality. Possible scores range from 0 to 164, although scores typically range from 0 to 50 for 80 % of patients in VACS-VC. A higher score indicates greater burden of disease (each additional five points indicates approximately 20 % increased 5-year mortality risk). ART adherence was measured using pharmacy data.
Complete data were available for 227 women and 8,073 men. At ART initiation, compared with men, women were younger and more likely to be Black, less likely to have liver dysfunction, but more likely to have lower hemoglobin levels. Median VACS Index scores changed from ART initiation to 1 year after ART initiation: women’s scores went from 41 to 28 for women (13 point improvement) and men’s from 42 to 27 for men (15 point improvement). In multivariable regression, women had 3.6 point worse scores than men after 1 year on ART (p = 0.002); this difference decreased to 3.2 points after adjusting for adherence (p = 0.004).
In VA, compared to men, women experienced less improvement in overall burden of disease after 1 year of HIV treatment. Further study is needed to elucidate the modifiable factors that may explain this disparity.
PMCID: PMC3695278  PMID: 23807068
women; Veterans; HIV; health care disparities; burden of illness
15.  Risk of Heart Failure With Human Immunodeficiency Virus in the Absence of Prior Diagnosis of Coronary Heart Disease 
Archives of internal medicine  2011;171(8):737-743.
Whether human immunodeficiency virus (HIV) infection is a risk factor for heart failure (HF) is not clear. The presence of coronary heart disease and alcohol consumption in this population may confound this association.
To determine whether HIV infection is a risk factor for incident HF, we conducted a population-based, retrospective cohort study of HIV-infected and HIV-uninfected veterans enrolled in the Veterans Aging Cohort Study Virtual Cohort (VACS-VC) and the 1999 Large Health Study of Veteran Enrollees (LHS) from January 1, 2000, to July 31, 2007.
There were 8486 participants (28.2% HIV-infected) enrolled in the VACS-VC who also participated in the 1999 LHS. During the median 7.3 years of follow-up, 286 incident HF events occurred. Age- and race/ethnicity–adjusted HF rates among HIV-infected and HIV-uninfected veterans were 7.12 (95% confidence interval [CI],6.90-7.34) and 4.82 (95% CI, 4.72-4.91) per 1000 person-years, respectively. Compared with HIV-uninfected veterans, those who were HIV infected had an increased risk ofHF (adjusted hazard ratio [HR], 1.81; 95% CI, 1.39-2.36). This association persisted among veterans who did not have a coronary heart disease event or a diagnosis related to alcohol abuse or dependence before the incident HF event (adjusted HR, 1.96; 95% CI, 1.29-2.98). Compared with HIV-uninfected veterans, those who were HIV infected with a baseline Human immunodeficiency virus 1 (HIV-1) RNA level of 500 or more copies/mL had a higher risk of HF (adjusted HR, 2.28; 95% CI, 1.57-3.32), while those with baseline and a recent HIV-1 RNA level less than 500 copies/mL did not (adjusted HR, 1.10; 95% CI, 0.64-1.89; P< .001 for comparison between high and low HIV-1 RNA groups).
Our data suggest that HIV infection is a risk factor for HF. Ongoing viral replication is associated with a higher risk of developing HF.
PMCID: PMC3687533  PMID: 21518940
16.  Do Patterns of Comorbidity Vary by HIV Status, Age, and HIV Severity? 
Patterns of comorbidity among persons with human immunodeficiency virus (HIV) are not well described. We compared comorbidity among veterans with and without HIV infection. The sample consisted of 33,420 HIV-infected veterans and 66,840 HIV-uninfected veterans. We identified and clustered 11 comorbid conditions using validated International Classification of Diseases, 9th Revision, Clinical Modification codes. We defined multimorbidity as the presence of conditions in all clusters. Models restricted to HIV-infected veterans were adjusted for CD4 cell count and viral load. Comorbidity was common (prevalence, 60%–63%), and prevalence varied by HIV status. Differences remained when the veterans were stratified by age. In multivariable analyses, older HIV-infected veterans were more likely to have substance use disorder and multimorbidity. Renal, vascular, and pulmonary diseases were associated with CD4 cell count <200 cells/mm3; hypertension was associated with CD4 cell count >200 cells/mm3. Comorbidity is the rule, and multimorbidity is common among veterans with HIV infection. Patterns of comorbidity differ substantially by HIV status, age, and HIV severity. Primary care guidelines require adaptation for persons with HIV infection.
PMCID: PMC3687553  PMID: 18190322
17.  MRSA nasal colonization burden and risk of MRSA infection 
Staphylococcus aureus nasal colonization burden has been identified as a risk factor for infection. This study evaluates methicillin-resistant S aureus (MRSA) nasal burden, as defined by the cycle threshold (Ct) and risk of subsequent infection.
In a retrospective cohort study, United States veterans were classified into 3 MRSA nasal colonization groups: noncarriers, low burden (Ct > 24 cycles), and high burden (Ct ≤ 24 cycles). MRSA infections were identified prospectively, and clinical information was obtained by chart review. Multivariate logistic regression assessed the association of MRSA nasal burden and risk of MRSA infection.
During 4-years of follow-up, 4.3% of noncarriers, 18.5% of low burden, and 17.2% of high burden developed a MRSA infection. In multivariate analysis, MRSA nasal colonization was a risk factor for MRSA infection (P = .008) with low burden (risk ratio [RR], 3.62; 95% confidence interval [CI]: 1.47–8.93) and high burden (RR, 2.71; 95% CI: 0.95–7.72) associated with subsequent MRSA infection when compared with noncarriers. When compared with low burden, high burden nasal carriers were not at increased risk of infection (RR, 0.75; 95% CI 0.36–1.55).
MRSA nasal colonization was a risk factor for MRSA infection. High nasal burden of MRSA did not increase the risk of infection.
PMCID: PMC3685139  PMID: 23261345
Staphylococcus aureus; Carriage quantification; Cycle threshold
18.  Reduction of Methicillin-Resistant Staphylococcus aureus Infection among Veterans in Atlanta 
Describe local changes in the incidence of community-onset and hospital-onset methicillin-resistant Staphylococcus aureus (MRSA) infection and evaluate the impact of MRSA active surveillance on hospital-onset infection.
Observational study using prospectively collected data.
Atlanta Veterans Affairs Medical Center (AVAMC).
All patients seen at the AVAMC over an 8-year period with clinically and microbiologically proven MRSA infection.
All clinical cultures positive for MRSA were prospectively identified, and corresponding clinical data were reviewed. MRSA infections were classified into standard clinical and epidemiologic categories. The Veterans Health Administration implemented the MRSA directive in October 2007, which required active surveillance cultures in acute care settings.
The incidence of community-onset MRSA infection peaked in 2007 at 5.45 MRSA infections per 1,000 veterans and decreased to 3.14 infections per 1,000 veterans in 2011 (P ≤ .001 for trend). Clinical and epidemiologic categories of MRSA infections did not change throughout the study period. The prevalence of nasal MRSA colonization among veterans admitted to AVAMC decreased from 15.8% in 2007 to 11.2% in 2011 (P < .001 for trend). The rate of intensive care unit (ICU)–related hospital-onset MRSA infection decreased from October 2005 through March 2007, before the MRSA directive. Rates of ICU-related hospital-onset MRSA infection remained stable after the implementation of active surveillance cultures. No change was observed in rates of non-ICU-related hospital-onset MRSA infection.
Our study of the AVAMC population over an 8-year period shows a consistent trend of reduction in the incidence of MRSA infection in both the community and healthcare settings. The etiology of this reduction is most likely multifactorial.
PMCID: PMC3677855  PMID: 23221194
19.  Methicillin-Resistant Staphylococcus aureus Colonization of the Groin and Risk for Clinical Infection among HIV-infected Adults 
Emerging Infectious Diseases  2013;19(4):623-629.
Data on the interaction between methicillin-resistant Staphylococcus aureus (MRSA) colonization and clinical infection are limited. During 2007–2008, we enrolled HIV-infected adults in Atlanta, Georgia, USA, in a prospective cohort study. Nares and groin swab specimens were cultured for S. aureus at enrollment and after 6 and 12 months. MRSA colonization was detected in 13%–15% of HIV-infected participants (n = 600, 98% male) at baseline, 6 months, and 12 months. MRSA colonization was detected in the nares only (41%), groin only (21%), and at both sites (38%). Over a median of 2.1 years of follow-up, 29 MRSA clinical infections occurred in 25 participants. In multivariate analysis, MRSA clinical infection was significantly associated with MRSA colonization of the groin (adjusted risk ratio 4.8) and a history of MRSA infection (adjusted risk ratio 3.1). MRSA prevention strategies that can effectively prevent or eliminate groin colonization are likely necessary to reduce clinical infections in this population.
PMCID: PMC3647417  PMID: 23631854
HIV; methicillin-resistant Staphylococcus aureus; colonization; viruses; bacteria; Georgia; MRSA; staphylococci
20.  HIV as an Independent Risk Factor for Incident Lung Cancer 
AIDS (London, England)  2012;26(8):1017-1025.
PMCID: PMC3580210  PMID: 22382152
Human Immunodeficiency Virus (HIV); lung cancer; incidence; smoking; immunosuppression; non-AIDS defining malignancy
21.  Replication-Independent Expression of Anti-Apoptosis Marker Genes in Human Peripheral Blood Mononuclear Cells Infected with the Wild-Type HIV-1 and Reverse Transcriptase Variants 
Viral Immunology  2012;25(1):12-20.
Clinical trials with highly-active antiretroviral therapy (HAART) have shown that a substantial number of patients continue to show a decrease in viral load and/or increase or stable CD4+ T-cell numbers even in the presence of multidrug resistant (MDR) viruses. We compared replication capacity (RC) and expression of anti-apoptosis marker genes (AAMGs) in human peripheral blood mononuclear (PBM) cells infected with NL4-3 (wild-type; WT) and mutant viruses. Replication kinetics assays showed a significant decrease in RC of all mutant viruses in comparison to the WT virus. The viruses containing patient-derived MDR RT without the K65R mutation (PSD5.2) replicated efficiently in comparison to the viruses with MDR RT containing the K65R mutation (PSD5.1), or the single mutations K65R and M184V. Compared with WT, a significant decrease in RCs of viruses: K65R (RC=0.39±0.02; p≤0.0001), M184V (RC=0.72±0.04; p≤0.0001), PSD5.1 (RC=0.32±0.04; p≤0.0001), and PSD5.2 (RC=0.90±0.04; p=0.002) was observed on day 10. RT-PCR-based apoptosis array was performed on total cellular RNA. Recombinant virus PSD5.2 showed a 1.5- to 6-fold upregulation in 8 AAMGs (AKT1, BAG3, BCL2A1, BFAR, BIRC2, BNIP1, BNIP3, and CFLAR) on day 1 and day 7 post-infection with respect to WT virus. PSD5.1 showed upregulation of only one gene (BAG1) on day 1 (1.75-fold) and day 7 (1.97-fold). Point mutant K65R showed a 1.5- to 4-fold upregulation of six AAMGs on day 7. Viruses with the M184V mutation showed upregulation of only one gene (BAG1). These observations indicate that the upregulation of specific AAMGs may not be dependent on the RCs of HIV-I variants, and that the possible interaction among mutated RT residues and viral and/or host proteins may induce CD4+ T-cell-protective anti-apoptosis proteins.
PMCID: PMC3271366  PMID: 22239233
22.  HIV-Associated Lung Cancer in the Era of Highly Active Antiretroviral Therapy (HAART) 
Cancer  2011;118(1):164-172.
Lung cancer is the leading cause of death among non-acquired immunodeficiency syndrome (AIDS) defining malignancies. Since highly active anti-retroviral therapy (HAART) has improved survival for human immunodeficiency virus (HIV) patients, we evaluated lung cancer outcomes in the HAART era.
HIV-positive patients diagnosed with lung cancer in our institution during the HAART era (1995-2008) were analyzed. Patient charts were reviewed for clinical and laboratory data. CD4 count at diagnosis was treated as a continuous variable and subcategorized into distinct variables with 3 cut-off points (50, 200, & 500 μl). Pearson’s correlation coefficients were estimated for each covariate studied. Survival was determined by the Kaplan-Meier method.
Out of 80 patients, 73 had non-small cell lung cancer. Baseline characteristics were: median age-52 yrs; male-80%; African American-84%; injection drug use-25%; smokers-100%; and prior exposure to antiretroviral agents-55%. Mean CD4 count and viral load were 304 μL and 82,420 copies/ml, respectively at cancer diagnosis. The latency between diagnosis of HIV and lung cancer was significantly shorter in women (4.1 yrs vs. 7.7 yrs, P=0.02) and 71% of the patients received anti-cancer therapy. The 1- and 3-year survival rates were 31% and 4% overall. Grade 3/4 toxicities occurred in 60% with chemo-radiation vs. 36% with chemotherapy. Cancer-related survival was better for patients with CD4 count >200 (P=0.0298) and >500 (P=0.0076).
The latency from diagnosis of HIV to lung cancer was significantly shorter for women. Although outcomes for lung cancer patients with HIV remain poor, high CD4 count is associated with an improved lung cancer-related survival.
PMCID: PMC3184336  PMID: 21713759
lung cancer; HIV; survival; anti-retroviral therapy; HAART
23.  Validating Smoking Data From the Veteran’s Affairs Health Factors Dataset, an Electronic Data Source 
Nicotine & Tobacco Research  2011;13(12):1233-1239.
We assessed smoking data from the Veterans Health Administration (VHA) electronic medical record (EMR) Health Factors dataset.
To assess the validity of the EMR Health Factors smoking data, we first created an algorithm to convert text entries into a 3-category smoking variable (never, former, and current). We compared this EMR smoking variable to 2 different sources of patient self-reported smoking survey data: (a) 6,816 HIV-infected and -uninfected participants in the 8-site Veterans Aging Cohort Study (VACS-8) and (b) a subset of 13,689 participants from the national VACS Virtual Cohort (VACS-VC), who also completed the 1999 Large Health Study (LHS) survey. Sensitivity, specificity, and kappa statistics were used to evaluate agreement of EMR Health Factors smoking data with self-report smoking data.
For the EMR Health Factors and VACS-8 comparison of current, former, and never smoking categories, the kappa statistic was .66. For EMR Health Factors and VACS-VC/LHS comparison of smoking, the kappa statistic was .61.
Based on kappa statistics, agreement between the EMR Health Factors and survey sources is substantial. Identification of current smokers nationally within the VHA can be used in future studies to track smoking status over time, to evaluate smoking interventions, and to adjust for smoking status in research. Our methodology may provide insights for other organizations seeking to use EMR data for accurate determination of smoking status.
PMCID: PMC3223583  PMID: 21911825
24.  FIB-4 index is associated with hepatocellular carcinoma risk in HIV-infected patients 
Chronic inflammation caused by hepatitis B virus infection, hepatitis C virus infection, and/or heavy alcohol use can lead to fibrosis, cirrhosis, and eventually hepatocellular carcinoma (HCC). FIB-4 is an index score calculated from platelet count, alanine transaminase, aspartate transaminase, and age that predicts fibrosis and cirrhosis. We hypothesized that high FIB-4 would be associated with development of HCC in HIV-infected persons, who are at high risk due to high prevalence of viral hepatitis and alcohol consumption, and possibly due to HIV infection itself.
Using proportional hazards models, we tested this hypothesis among 22,980 HIV-infected men from the Veterans Aging Cohort Study. We identified incident HCC cases from the VA Central Cancer Registry.
During follow-up, there were 112 incident HCC diagnoses. The age-and race/ethnic group-adjusted HR was 4.2 (95% CI: 2.4, 7.4)for intermediate FIB-4 and 13.0 (95% CI: 7.2, 23.4) for high FIB-4, compared to low FIB-4. After further adjustment for enrollment year, CD4 count, HIV-1 RNA level, antiretroviral therapy use, hepatitis B and C virus infection, alcohol abuse/dependency, and diabetes, FIB-4 remained a strong, significant, independent risk factor for HCC. The multivariate-adjusted HR was 3.6 (95% CI: 2.1, 6.4) for intermediate FIB-4 and 9.6 (95% CI: 5.2, 17.4) for high FIB-4.
Calculated from routine, non-invasive laboratory tests, FIB-4 is a strong, independent HCC risk factor in HIV-infected patients.
FIB-4 might prove valuable as an easily measured index to identify those at highest risk for HCC, even prior to development of clinical cirrhosis.
PMCID: PMC3237927  PMID: 22028407
hepatocellular carcinoma; FIB-4; HIV; liver neoplasms; hepatic fibrosis
25.  Cepheid Xpert MRSA Cycle Threshold in Discordant Colonization Results and as a Quantitative Measure of Nasal Colonization Burden 
Journal of Clinical Microbiology  2012;50(6):2079-2081.
We analyzed the cycle threshold (CT) of PCR surveillance MRSA swabs obtained from veterans. Lower CT on admission was associated with a positive culture from nasal swabs at discharge. Compared to PCR, direct plating of nasal swabs performed poorly, especially for patients with an elevated CT. The CT is strongly correlated with quantitative nasal cultures. Clinical and infection control applications of the CT have yet to be defined and warrant further evaluation.
PMCID: PMC3372118  PMID: 22442322

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