Adam Chow

Risk of Cardiovascular Events Associated With Current Exposure to HIV Antiretroviral Therapies in a US Veteran Population

BACKGROUND To characterize the association of antiretroviral drug combinations on risk of cardiovascular events. METHODS Certain antiretroviral medications for human immunodeficiency virus (HIV) have been implicated in increasing risk of cardiovascular disease. However, antiretroviral drugs are typically prescribed in combination. We characterized the association of current exposure to antiretroviral drug combinations on risk of cardiovascular events including myocardial infarction, stroke, percutaneous coronary intervention, and coronary artery bypass surgery. We used the Veterans Health Administration Clinical Case Registry to analyze data from 24 510 patients infected with HIV from January 1996 through December 2009. We assessed the association of current exposure to 15 antiretroviral drugs and 23 prespecified combinations of agents on the risk of cardiovascular event by using marginal structural models and Cox models extended to accommodate time-dependent variables. RESULTS Over 164 059 person-years of follow-up, 934 patients had a cardiovascular event. Current exposure to abacavir, efavirenz, lamivudine, and zidovudine was significantly associated with increased risk of cardiovascular event, with odds ratios ranging from 1.40 to 1.53. Five combinations were significantly associated with increased risk of cardiovascular event, all of which involved lamivudine. One of these-efavirenz, lamivudine, and zidovudine-was the second most commonly used combination and was associated with a risk of cardiovascular event that is 1.60 times that of patients not currently exposed to the combination (odds ratio = 1.60, 95% confidence interval, 1.25-2.04). CONCLUSIONS In the VA cohort, exposure to both individual drugs and drug combinations was associated with modestly increased risk of a cardiovascular event.

Reducing costs of acute care for ambulatory care-sensitive medical conditions: the central roles of comorbid mental illness.

Background:New patient-centered models of ambulatory care aim to substitute better primary care for preventable acute care within existing primary care practices. This study aims to identify whether mental illness and other characteristics of primary care patients are related to risk for an acute event for an ambulatory care-sensitive condition (ACSC). Methods:We conducted a 2-year, longitudinal analysis comparing ambulatory care-sensitive admissions and emergency department (ED) visits for a cohort of 18,526 primary care patients followed in 5 veterans affairs (VA) primary care sites. We compared rates, risks, and costs of ACSC-related acute events during a follow-up year for patients with and without mental illness seen during the previous year in primary care. Results:The 12-month rate of ACSC admissions was 31.7 admissions per 1000 patients with mental health diagnoses compared with 21.0 admissions per 1000 patients without (P=0.0009). The ACSC-associated ED visit rate was also significantly higher (P<0.0001). In adjusted analyses controlling for demographics, chronic disease, illness severity, and prior ambulatory care, those with depression or drug use disorders had higher odds of receiving ACSC-related acute care (odds ratio=1.10, 95% confidence interval: 1.03, 1.17 for depression; odds ratio=1.48, 95% confidence interval: 1.05, 1.99 for drug use disorders). Costs per admission and ED visit were similar across patient groups. Higher medication use and lower medication regimen complexity were significantly associated with decreased risk for ACSC events. Conclusions:Prior mental health diagnoses and medication use were independent risk factors for ACSC-related acute care. These risk factors require focused attention if the full benefits of new primary care models are to be achieved.

Determinants of the cost of health services used by veterans with HIV.

BackgroundThe effect of adherence, treatment failure, and comorbidities on the cost of HIV care is not well understood. ObjectiveTo characterize the cost of HIV care including combination antiretroviral treatment (ART). Research DesignObservational study of administrative data. SubjectsTotal 1896 randomly selected HIV-infected patients and 288 trial participants with multidrug-resistant HIV seen at the US Veterans Health Administration (VHA). MeasuresComorbidities, cost, pharmacy, and laboratory data. ResultsMany HIV-infected patients (24.5%) of the random sample did not receive ART. Outpatient pharmacy accounted for 62.8% of the costs of patients highly adherent with ART, 32.2% of the cost of those with lower adherence, and 6.2% of the cost of those not receiving ART. Compared with patients not receiving ART, high adherence was associated with lower hospital cost, but no greater total cost. Individuals with a low CD4 count (<50 cells/mm3) incurred 1.9 times the cost of patients with counts >500. Most patients had medical, psychiatric, or substance abuse comorbidities. These conditions were associated with greater cost. Trial participants were less likely to have psychiatric and substance abuse comorbidities than the random sample of VHA patients with HIV. ConclusionsPatients receiving combination ART had higher medication costs but lower acute hospital cost. Poor control of HIV was associated with higher cost. The cost of psychiatric, substance abuse, rehabilitation, and long-term care and medications other than ART, often overlooked in HIV studies, was substantial.

Effect of Treatment Interruption and Intensification of Antiretroviral Therapy on Health-Related Quality of Life in Patients with Advanced HIV: A Randomized, Controlled Trial

Background. The effect of antiretroviral therapy (ART) interruption or intensification on health-related quality of life (HRQoL) in advanced HIV patients is unknown. Objective. To assess the impact of temporary treatment interruption and intensification of ART on HRQoL. Design. A 2 x 2 factorial open label randomized controlled trial. Setting. Hospitals in the United States, Canada, and the United Kingdom. Patients. Multidrug resistant (MDR) HIV patients. Intervention. Patients were randomized to receive a 12-wk interruption or not, and ART intensification or standard ART. Measurements. The Health Utilities Index (HUI3), EQ-5D, standard gamble (SG), time tradeoff (TTO), visual analog scale (VAS), and the Medical Outcomes Study HIV Health Survey (MOS-HIV). Results. There were no significant differences in HRQoL among the four groups during follow-up; however, there was a temporary significant decline in HRQoL on some measures within the interruption group during interruption (HUI3 −0.05, P = 0.03; VAS −5.9, P = 0.002; physical health summary −2.9, P = 0.001; mental health summary −1.9, P = 0.02). Scores declined slightly overall during follow-up. Multivariate analysis showed significantly lower HRQoL associated with some clinical events. Limitations. The results may not apply to HIV patients who have not experienced multiple treatment failures or who have not developed MDR HIV. Conclusions. Temporary ART interruption and ART intensification provided neither superior nor inferior HRQoL compared with no interruption and standard ART. Among surviving patients, HRQoL scores declined only slightly over years of follow-up in this advanced HIV cohort; however, approximately one-third of patients died during the trial follow up. Lower HRQoL was associated with adverse clinical events.

Impact of Medical Home Implementation Through Evidence-based Quality Improvement on Utilization and Costs

Background:Evidence-based quality improvement (EBQI) methods may facilitate practice redesign for more effective implementation of the patient-centered medical home (PCMH). Objective:We assessed changes in health care utilization and costs for patients receiving care from practices using an EBQI approach to implement PCMH and comparison practices over a 5-year period. Research Design:We used longitudinal, electronic data from patients in 6 practices using EBQI and 28 comparison practices implementing standard PCMH for 1 year before and 4 years after PCMH implementation. We analyzed trends in utilization and costs using bivariate analyses and independent effects of EBQI status on outcomes using multivariate regressions adjusting for year, patient and clinic factors, and patient random effects for repeated measures. Subjects:A total of 136,856 patients using Veterans Affairs primary care. Measures:Veterans Affairs ambulatory care encounters, emergency department visits, admissions, and total health care costs per patient. Results:After PCMH implementation, overall utilization for primary care, specialty care, and mental health/substance abuse care decreased, whereas utilization for telephone care increased among all practices. Patients also had fewer hospitalizations and lower costs per patient. In adjusted analyses, EBQI practice was independently associated with fewer primary care (IRR=0.85), specialty care (IRR=0.83), and mental health care encounters (IRR=0.69); these effects attenuated over time (all P<0.01). There was no independent effect of EBQI on prescription drug use, acute care, health care costs, or mortality rate relative to comparison practices. Conclusion:EBQI methods enhanced the effects of PCMH implementation by reducing ambulatory care while increasing non-face-to-face care.

Trends and Patient Characteristics Associated with Tobacco Pharmacotherapy Dispensed in the Veterans Health Administration

Introduction There is evidence suggesting that certain subgroups of people who use tobacco do not receive tobacco pharmacology as consistently as others. Methods This retrospective, cohort study examined the trend in the use of cessation pharmacotherapy from 2004 to 2013 using Veterans Health Administration (VHA) administrative data. Among Veterans who used tobacco in the fiscal year (FY) 2011 and had not received pharmacotherapy in the prior year, multivariable Cox regression was used to assess the independent associations between patient clinical and demographic characteristics and pharmacotherapy initiation in the 6-months follow-up period. Results Smoking cessation pharmacotherapy in the VHA increased from 13.8% in 2004 to 25.6% in 2013. In 2011, Veterans (N = 838309) who were more likely to newly receive pharmacotherapy included those with psychiatric disorders (depression, bipolar disorder, non-alcohol substance use disorder, other anxiety, and post-traumatic stress disorder), chronic pulmonary disease, peripheral vascular disorders, and younger Veterans (adjusted rate ratios (ARRs) ranged from 1.03 to 1.92, all p < .001). Veterans less likely to receive pharmacotherapy were those with schizophrenia or other psychosis, males, Hispanics, and those with a medical condition (uncomplicated diabetes, uncomplicated hypertension, fluid and electrolyte disorders, cardiac arrhythmia, valvular disease, hypothyroidism, acquired immunodeficiency syndrome/human immunodeficiency virus, deficiency anemia, renal failure, paralysis, coagulopathy, metastatic cancer, and other neurological disorders) (ARRs ranged from 0.74 to 0.93, all p < .001). Conclusions Although VHA cessation pharmacotherapy use nearly doubled from 13.8% in 2004 to 25.6% in 2013, reaching undertreated subgroups, especially those with medical comorbidities, may improve cessation outcomes. Implications Despite evidence that demographics influence the use of pharmacotherapy in smoking cessation, there is limited and contradictory information regarding how psychiatric and chronic medical illnesses affect pharmacotherapy use. Administrative data were used to determine trends and patient characteristics of those receiving pharmacotherapy to aid in smoking cessation in the Veterans Health Administration. From 2004 to 2013, pharmacotherapy use increased from 13.8% to 25.6% of current smokers. Factors associated with increased pharmacotherapy initiation were psychiatric disorders, chronic pulmonary disease, peripheral vascular disorders, and younger age. Veterans with schizophrenia or other psychosis, males, Hispanics, and most medical conditions were less likely to receive pharmacotherapy.

The Relationship Between Same-Day Access and Continuity in Primary Care and Emergency Department Visits

We examined how emergency department (ED) visits for potentially preventable, mental health, and other diagnoses were related to same-day access and provider continuity in primary care using administrative data from 71,296 patients in 22 VHA clinics over a three-year period. ED visits were categorized as non-emergent; primary care treatable; preventable; not preventable; or mental health-related. We conducted multi-level regression models adjusted for patient and clinic factors. More same-day access significantly predicted fewer non-emergent and primary care treatable ED visits while continuity was not significantly related to any type of ED visit. Neither measure was related to ED visits for mental health problems.

Comparing chronic condition rates using ICD-9 and ICD-10 in VA patients FY2014–2016

BackgroundManagement of patients with chronic conditions relies on accurate measurement. It is unknown how transition to the ICD-10 coding system affected reporting of chronic condition rates over time. We measured chronic condition rates 2 years before and 1 year after the transition to ICD-10 to examine changes in prevalence rates and potential measurement issues in the Veterans Affairs (VA) health care system.MethodsWe developed definitions for 34 chronic conditions using ICD-9 and ICD-10 codes and compared the prevalence rates of these conditions from FY2014 to 2016 in a 20% random sample (1.0 million) of all VA patients. In each year we estimated the total number of patients diagnosed with the conditions. We regressed each condition on an indicator of ICD-10 (versus ICD-9) measurement to obtain the odds ratio associated with ICD-10.ResultsCondition prevalence estimates were similar for most conditions before and after ICD-10 transition. We found significant changes in a few exceptions. Alzheimer’s disease and spinal cord injury had more than twice the odds of being measured with ICD-10 compared to ICD-9. HIV/AIDS had one-third the odds, and arthritis had half the odds of being measured with ICD-10. Alcohol dependence and tobacco/nicotine dependence had half the odds of being measured in ICD-10.ConclusionMany chronic condition rates were consistent from FY14–16, and there did not appear to be widespread undercoding of conditions after ICD-10 transition. It is unknown whether increased sensitivity or undercoding led to decreases in mental health conditions.

Effectiveness of tobacco cessation pharmacotherapy in the Veterans Health Administration

Introduction In 2003, the Veterans Health Administration (VHA) implemented a directive that cessation pharmacotherapy be made available to all who use tobacco and are interested in quitting. Despite the efficacy of cessation pharmacotherapy shown in clinical trials, the generalisability of the results in real-world settings has been challenged. Hence, the specific aim of this study was to determine the effectiveness of cessation pharmacotherapies in the VHA. Methods This retrospective cohort study used VHA’s electronic medical record data to compare quit rates among those who use tobacco and who did vs. did not receive any type of cessation pharmacotherapy. Included were 589 862 Veterans identified as current tobacco users during fiscal year 2011 who had not received cessation pharmacotherapy in the prior 12 months. Following a 6-month period to assess treatment, quit rates among those who were treated versus untreated were compared during the 7–18 months (12 months) post-treatment follow-up period. The estimated treatment effect was calculated from a logistic regression model adjusting for inverse probability of treatment weights (IPTWs) and covariates. Marginal probabilities of quitting were also obtained among those treated versus untreated. Results Adjusting for IPTWs and covariates, the odds of quitting were 24% higher among those treated versus untreated (OR=1.24, 95% CI 1.23 to 1.25, p<0.001). The marginal probabilities of quitting were 16.7% for the untreated versus 19.8% for the treated based on the weighted model. Conclusion The increased quit rates among Veterans treated support the effectiveness and continuation of the VHA tobacco cessation pharmacotherapy policy.