VA Cooperative Studies Program (CSP)

Published Studies

These are the last three years of primary analysis publication(s) for CSP research studies. A link to the full text version is provided for those that don’t require a subscription to the journal. A link to a summary is provided for the few where a subscription is required.

CSP #468F: Follow Up Study for Treatment of Parkinson’s Disease with Deep Brain Stimulation

• Ostrem, J.L., Luo, P., Weaver, F.M., Follett, K., Rothlind, J., Galifianakis, N.B., Lai, E.C., Bronstein, J., Duda, J., Holloway, K. and Sarwar, A., 2025. 10-year clinical outcomes of subthalamic nucleus versus pallidal deep brain stimulation for Parkinson’s disease: VA/NINDS CSP# 468F. Frontiers in Neurology, 16, p.1728999. doi: 10.3389/fneur.2025.1728999 

CSP #572: VA Augmentation and Switching Treatments for Improving Depression Outcomes (VAST-D)

• Zisook, S., Moutier, C.Y., Rush, A.J., Johnson, G.R., Tal, I., Chen, P.J., Davis, L.L., Hicks, P.B., Wilcox, J., Planeta, B. and Lauro, K.W., 2024. Effect of next-step antidepressant treatment on suicidal ideation: findings from the VAST-D trial. Psychological medicine, 54(6), pp.1172-1183. doi:10.1017/S0033291723003008

CSP #592: Efficacy and Safety of Implantable Cardioverter-Defibrillator (ICD) Implantation in the Elderly

• Singh, S.N., Wininger, M., Raitt, M., Adabag, S., Moore, H., Rottman, J.N., Scrymgeour, A., Zhang, J., Zheng, K., Guarino, P. and Kyriakides, T.C., 2024. Efficacy and safety of implantable cardioverter-defibrillator implantation in the elderly—The I-70 Study: A randomized clinical trial. Heart Rhythm O2, 5(6), pp.365-373. doi: 10.1016/j.hroo.2024.04.010

CSP #596: Optimal Treatment for Recurrent Clostridium Difficile (OpTION)

• Johnson, S., Gerding, D.N., Donskey, C.J., Feng, H., Johnson, N., Johnson, M., Carlson, K.M., Ge, L., Goldberg, A.M., Reda, D.J. and Climo, M.W., 2026. Vancomycin Taper and Pulse or Fidaxomicin for Recurrent C. difficile Infection. NEJM Evidence, 5(8). doi: 10.1056/EVIDoa2600016

CSP #599: Transfusion Trigger After Operations in High Cardiac Risk Patients (TOP)

• Kougias, P., Sharath, S.E., Zhan, M., Carson, J.L., Norman, L.E., Mi, Z., Pal, R., Dosluoglu, H., Modrall, J.G., Sarosi, G.A. and Nelson, P., 2025. Liberal or restrictive postoperative transfusion in patients at high cardiac risk: the TOP randomized clinical trial. JAMA. doi: 10.1001/jama.2025.20841 _{(Editorialized in: Jacobs, J.W. and Bloch, E.M., 2025. Postoperative Transfusion in Patients at High Cardiac Risk: Evidence, Uncertainty, and Nuance. JAMA. doi: 10.1001/jama.2025.21559)}

CSP #2003: Exoskeletal-Assisted Walking in Persons with Spinal Cord Injuries (SCI): Impact on Quality of Life

• Spungen, A.M., Dematt, E.J., Biswas, K., Jones, K.M., Mi, Z., Snodgrass, A.J., Morin, K., Asselin, P.K., Cirnigliaro, C.M., Kirshblum, S. and Gorman, P.H., 2024. Exoskeletal-assisted walking in veterans with paralysis: a randomized clinical trial. JAMA network open, 7(9), pp.e2431501-e2431501. doi: 10.1001/jamanetworkopen.2024.31501

CSP #2004: Microbiota or Placebo after Antimicrobial Therapy for Recurrent C. difficile at Home (MATCH)

• Drekonja, D.M., Shaukat, A., Huang, Y., Zhang, J.H., Reinink, A.R., Nugent, S., Dominitz, J.A., Davis-Karim, A., Gerding, D.N. and Kyriakides, T.C., 2025. A randomized controlled trial of efficacy and safety of Fecal Microbiota Transplant for preventing recurrent Clostridioides difficile infection. Clinical Infectious Diseases, 80(1), pp.52-60. doi: 10.1093/cid/ciaf032.

CSP #2006: Genomics of Gulf War Illness in Veterans

• He, J., Pathak, G.A., Cabrera-Mendoza, B., Qiu, D., Zawack, K., Steele, L., Quaden, R., Harrington, K.M., Gifford, E.J., Aslan, M. and Helmer, D.A., 2026. Observational and genetically-informed characterization of Gulf War Illness symptoms in 1990–1991 Gulf War deployed Veterans and non-deployed Gulf War Era Veterans. Environmental Health. doi: 10.1186/s12940-026-01316-5
  
  
• Pathak, G.A., Koller, D., Cabrera-Mendoza, B., Nono Djotsa, A.B., Wendt, F.R., De Lillo, A., Friligkou, E., He, J., Kouakou, M.R., Duong, L.M. and Vahey, J., 2025. Unraveling the genetics of gulf war illness in diverse participants enrolled in the million veteran program. Human Molecular Genetics, p.ddaf075.
  
  
• Harrington, K.M., Quaden, R., Steele, L., Helmer, D.A., Hauser, E.R., Ahmed, S.T., Aslan, M., Radhakrishnan, K., Honerlaw, J., Nguyen, X.M.T. and Muralidhar, S., 2024. The Million Veteran Program 1990–1991 Gulf War Era Survey: An Evaluation of Veteran Response, Characteristics, and Representativeness of the Gulf War Era Veteran Population. International Journal of Environmental Research and Public Health, 21(1), p.72. doi: 10.3390/ijerph21010072

• Steele, L., Quaden, R., Ahmed, S.T., Harrington, K.M., Duong, L.M., Ko, J., Gifford, E.J., Polimanti, R., Gaziano, J.M., Aslan, M. and Helmer, D.A., 2024. Association of deployment characteristics and exposures with persistent ill health among 1990-1991 Gulf War veterans in the VA Million Veteran Program. Environmental Health, 23(1), p.92. doi: 10.1186/s12940-024-01118-7

• Wendt, F.R., Pathak, G.A., Vahey, J., Qin, X., Koller, D., Cabrera-Mendoza, B., Haeny, A., Harrington, K.M., Rajeevan, N., Duong, L.M. and Levey, D.F., 2023. Modeling the longitudinal changes of ancestry diversity in the Million Veteran Program. Human Genomics, 17(1), p.46. doi: 10.1186/s40246-023-00487
  
  
• Radhakrishnan, K., Hauser, E.R., Polimanti, R., Helmer, D.A., Provenzale, D., McNeil, R.B., Maffucci, A., Quaden, R., Zhao, H., Whitbourne, S.B. and Harrington, K.M., 2021. Genomics of Gulf War Illness in US veterans who served during the 1990–1991 Persian Gulf War: methods and rationale for Veterans Affairs Cooperative Study #2006. Brain sciences, 11(7), p.845. doi: 10.3390/brainsci11070845.

CSP #2038: COVID-19 Pharmacotherapy Effectiveness in the VA Healthcare System (COPE-VA)

• Ioannou, G.N., Berry, K., Yan, L., Huang, Y., Lin, H.M., Bui, D., Hynes, D.M., Boyko, E.J., Ferguson, J.M., Aslan, M. and Bajema, K.L., 2026. Effectiveness of the 2024–2025 KP. 2 COVID-19 vaccines in the United States during long-term follow-up. Nature Communications, 17(1), pp.1-11. doi: 10.1038/s41467-025-67796-0
  
  
• Bajema, K.L., Bui, D.P., Yan, L., Li, Y., Rajeevan, N., Vergun, R., Berry, K., Huang, Y., Lin, H.M., Aslan, M. and Ioannou, G.N., 2025. Severity and Long-Term Mortality of COVID-19, Influenza, and Respiratory Syncytial Virus. JAMA Internal Medicine,185(3):324–334. doi:10.1001/jamainternmed.2024.7452
  
  
• Bajema, K.L., Bui, D.P., Yan, L., Li, Y., Rajeevan, N., Vergun, R., Sriskantharajah, V., Hynes, D.M., Berry, K., Huang, Y. and Lin, H.M., 2025. Durability of respiratory syncytial virus vaccine effectiveness among US veterans. JAMA Internal Medicine. doi: 10.1001/jamainternmed.2025.6355
  
  
• Bajema, K.L., Yan, L., Berry, K., Bui, D., Lin, H.M., Huang, Y., Li, Y., Rajeevan, N., Maciejewski, M.L., Smith, V.A. and Bohnert, A.S., 2025. Impact of time zero designation on estimated COVID-19 antiviral effectiveness in observational studies. American journal of epidemiology, p.kwaf221. doi: 10.1093/aje/kwaf221
  
  
• Bajema, K.L., Yan, L., Li, Y., Argraves, S., Rajeevan, N., Fox, A., Vergun, R., Berry, K., Bui, D., Huang, Y. and Lin, H.M., 2025. Respiratory syncytial virus vaccine effectiveness among US veterans, September, 2023 to March, 2024: a target trial emulation study. The Lancet Infectious Diseases, Jan 20:S1473-3099(24)00796-5. doi: 10.1016/s1473-3099(24)00796-5
  
  
• Bui, D.P., Hynes, D.M., Wong, E., Vergun, R., Yan, L., Li, Y., Rajeevan, N., Berry, K., Lin, H.M., Huang, Y. and Govier, D.J., 2025. Budget impact of adopting nirmatrelvir-ritonavir for treating COVID-19 in a large integrated healthcare system. Open Forum Infectious Diseases, 12(10), ofaf596. US: Oxford University Press. doi: 10.1093/ofid/ofaf596
  
  
• Ioannou, G.N., Berry, K., Rajeevan, N., Li, Y., Yan, L., Huang, Y., Bui, D., Hynes, D.M., Rowneki, M., Hickok, A. and Niederhausen, M., 2025. Target Trial Emulation of Severe Acute Respiratory Syndrome Coronavirus 2 Infection Versus No Infection and Risk of Post–Coronavirus Disease 2019 Conditions in the Omicron Variant Versus Prior Eras. Clinical Infectious Diseases, p.ciaf087. doi: 10.1093/cid/ciaf087
  
  
• Bui, D.P., Bajema, K.L., Huang, Y., Yan, L., Li, Y., Rajeevan, N., Berry, K., Rowneki, M., Argraves, S., Hynes, D.M. and Huang, G., 2024. Development of a prediction model for 30-day COVID-19 hospitalization and death in a national cohort of Veterans Health Administration patients–March 2022—April 2023. PloS one, 19(10), p.e0307235. doi: 10.1371/journal.pone.0307235
  
  
• Yan, L., Bui, D., Li, Y., Rajeevan, N., Rowneki, M., Berry, K., Argraves, S., Huang, Y., Hynes, D.M., Cunningham, F. and Huang, G.D., 2024. Identifying veterans who benefit from nirmatrelvir-ritonavir: a target trial emulation. Clinical Infectious Diseases, 79(3), pp.643-651.doi:10.1093/cid/ciae202
  
  
• Bajema, K.L., Berry, K., Streja, E., Rajeevan, N., Li, Y., Mutalik, P., Yan, L., Cunningham, F., Hynes, D.M., Rowneki, M. and Bohnert, A., 2023. Effectiveness of COVID-19 treatment with nirmatrelvir–ritonavir or molnupiravir among US veterans: target trial emulation studies with one-month and six-month outcomes. Annals of internal medicine, 176(6), pp.807-816. doi:10.7326/M22-3565
  
  
• Ioannou, G.N., Berry, K., Rajeevan, N., Li, Y., Mutalik, P., Yan, L., Bui, D., Cunningham, F., Hynes, D.M., Rowneki, M. and Bohnert, A., 2023.Effectiveness of nirmatrelvir–ritonavir against the development of post–COVID-19 conditions among US veterans: a target trial emulation. Annals of internal medicine, 176(11), pp.1486-1497. doi:10.7326/M23-1394

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