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VACS Family of EHR-based Cohorts

Diagram showing the relation of VACS Family of EHR-based Cohorts


Cohort Summary

  • Full national sample
  • N~13.5 million
  • All Veterans receiving care in the VA system

The largest of the VACS cohorts is VACS-National, which represents all ~13.5 million patients who have accessed VA care since 2000, with ~6 million patients accessing care annually. VACS-National is a rich, national resource of highly detailed EHR and other linked data already used to examine research questions on disease surveillance, prevention, risk prediction, and outcomes analysis on hepatitis C, COVID-19, HIV, cardiovascular, pulmonary, and other conditions. We have >100 variables cleaned and ready for analysis in VACS-National, including demographics, comorbidities, labs, vital signs, and other health behaviors.


Cohort Summary

  • HIV Study
  • 60,000 PWH, 120,000 PWoH
  • 1 PWH:2 PWoH demographically-matched

VACS-HIV is a cohort of >60,000 veterans with HIV and a one to two (>120,000) age-, race/ethnicity-, sex-, and clinical site-matched sample of veterans without HIV, assembled from national VA data beginning in 1997. Research in this cohort is used to understand the overall impact of HIV, HIV treatment, and comorbid conditions on morbidity and mortality. At the end of each fiscal year, this cohort is updated to include veterans with new diagnoses of HIV infection and matched controls receiving care in the same fiscal year.


Cohort Summary

  • 4,352 PWH; 4,561 PWoH
  • Consented survey sub-study
  • 1PWH:1PWoH
  • 9 VA sites
  • Patient & provider surveys
  • Linkage to EHR

VACS-HIV is complemented by a prospectively-consented, substudy cohort of veterans with and without HIV infection, in care at nine VA medical centers around the country. This in-depth cohort allows us to “get behind” gross associations with outcome, to better understand the likely complex and overlapping etiologies resulting in differences outcome and patient utilization. Since 2002, VACS-HIV Survey has consented and enrolled >7,000 patients (half persons with HIV [PWH], half demographically-matched persons without HIV [PWoH] in Atlanta, Baltimore, the Bronx, Dallas, Houston, Los Angeles, Manhattan/Brooklyn, Pittsburgh, and Washington, D.C.

In addition to having access to complete medical-record information (including pharmacy fills, laboratory data, pathology data, radiology data, and progress notes) and administrative data (including utilization and diagnostic codes), VACS-HIV Survey draws from several additional sources of data: (1) patient and provider surveys (quality of life, symptoms, adherence, alcohol use, drug use, health habits) at the time of the visit; (2) telephone interviews providing in-depth data on alcohol use and medication adherence; (3) banked serum, plasma, and blood pellets for future hypothesis testing; (4) The National VA Cancer Registry; (5)The QUERI Myocardial Infarction Registry; (6) The National Death Index Cause of Death File;and (7) Medicaid and Medicare Files for outside utilization.

VACS-HIV Biomarker

Cohort Summary

  • 1,730 PWH, 946 PWoH
  • Consented biomarker sub-study
  • 2 PWH:1 PWoH
  • Banked specimens, selected labs, DNA
  • Linkage to EHR + Survey

The VACS-HIV Biomarker substudy includes 1,730 persons with HIV (PWH) and 926 persons without HIV (PWoH). It is a consented biomarker substudy with banked specimens, select labs, and DNA with linkage to the electronic health records and survey cohort data.


Cohort Summary

  • 534 PWH at VACS Survey Sites
  • Consented biomarker substudy
  • Tripartite with KPHN (284 PWH), SHCS (451 PWH)
  • Banked specimens, selected labs, DNA
  • Linkage to EHR + MASH specific patient survey and pharmacist

PWH=Persons with HIV (HIV+)
PWoH=Persons without HIV (uninfected)

Medications, Alcohol, and Substance Use in HIV (MASH) is a tripartite study with VACS (N=534 PWH) Kaiser Permanente Northern California (KPNC, N=284 PWH), and the Swiss HIV Cohort Study (SHCS, N=451 PWH). It is a consented biomarker substudy with banked specimens, select labs, and DNA with linkage to the electronic health records and MASH specific patient survey and pharmacist surveys.