Target Trial Emulation Without Matching: A More Efficient Approach for Evaluating Vaccine Effectiveness Using Observational Data.

Λεπτομέρειες βιβλιογραφικής εγγραφής
Τίτλος: Target Trial Emulation Without Matching: A More Efficient Approach for Evaluating Vaccine Effectiveness Using Observational Data.
Συγγραφείς: Wu E; From the Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA., Rogawski McQuade E; Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA., Stensrud MJ; Department of Mathematics, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland., Nabi R; From the Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA., Benkeser D; From the Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA.
Πηγή: Epidemiology (Cambridge, Mass.) [Epidemiology] 2026 Sep 01; Vol. 37 (5), pp. 612-619. Date of Electronic Publication: 2026 Mar 30.
Τύπος έκδοσης: Journal Article
Γλώσσα: English
Στοιχεία περιοδικού: Publisher: Lippincott Williams & Wilkins Country of Publication: United States NLM ID: 9009644 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1531-5487 (Electronic) Linking ISSN: 10443983 NLM ISO Abbreviation: Epidemiology Subsets: MEDLINE
Imprint Name(s): Publication: <2000>- : Hagerstown, MD : Lippincott Williams & Wilkins
Original Publication: [Cambridge, MA : Blackwell Scientific Publications ; Chestnut Hill, MA : Epidemiology Resources, c1990-
Ιατρικοί όροι (MeSH): Vaccine Efficacy*/statistics & numerical data , COVID-19*/prevention & control , COVID-19*/epidemiology , COVID-19 Vaccines*/therapeutic use , Observational Studies as Topic*, Humans ; Child ; Child, Preschool ; Proportional Hazards Models ; SARS-CoV-2 ; Computer Simulation
Περίληψη: Real-world vaccine effectiveness (VE) has increasingly been studied using matching-based approaches, particularly in observational cohort studies that follow the target trial emulation framework. Although matching is appealing in its simplicity, it has important limitations in terms of clarity of the target estimand and the precision with which it is estimated. Moreover, defining causal estimands of VE requires care, because vaccine uptake often occurs over calendar time when infection dynamics may also be rapidly changing. We propose a causal estimand of VE that summarizes VE over calendar time, similar to how vaccine efficacy is summarized in randomized controlled trials. We describe the identification of our estimand and propose simple-to-implement estimators based on two hazard regression models. We apply our proposed estimator in simulations and in a study assessing the effectiveness of the Pfizer-BioNTech COVID-19 vaccine to prevent SARS-CoV-2 infections in children 5-11 years old. In both settings, we find that our proposed estimator yields similar scientific inferences while providing significant efficiency gains over commonly used matching-based estimators.
(Copyright © 2026 Wolters Kluwer Health, LLC. All rights reserved.)
Competing Interests: Disclosure: The authors report no conflicts of interest.
References: Hernán MA, Sauer BC, Hernáández-Díaz S, Platt R, Shrier I. Specifying a target trial prevents immortal time bias and other self-inflicted injuries in observational analyses. J Clin Epidemiol. 2016;79:70–75.
Hernán MA, Robins JM. Using big data to emulate a target trial when a randomized trial is not available. Am J Epidemiol. 2016;183:758–764.
Komura T, Watanabe M, Shioda K. Exploring the application of target trial emulation in vaccine evaluation: scoping review. Am J Epidemiol. 2025;194:3028–3040.
Dagan N, Barda N, Kepten E, et al. BNT162b2 mRNA COVID-19 vaccine in a nationwide mass vaccination setting. N Engl J Med. 2021;384:1412–1423.
Barda N, Dagan N, Cohen C, et al. Effectiveness of a third dose of the BNT162b2 mRNA COVID-19 vaccine for preventing severe outcomes in Israel: an observational study. Lancet. 2021;398:2093–2100.
Reis BY, Barda N, Leshchinsky M, et al. Effectiveness of BNT162b2 vaccine against delta variant in adolescents. N Engl J Med. 2021;385:2101–2103.
Ioannou GN, Locke ER, O’Hare AM, et al. COVID-19 vaccination effectiveness against infection or death in a national U.S. health care system. Ann Intern Med. 2022;175:352–361.
Cohen-Stavi CJ, Magen O, Barda N, et al. BNT162b2 vaccine effectiveness against Omicron in children 5 to 11 years of age. N Engl J Med. 2022;387:227–236.
Monge S, Rojas-Benedicto A, Olmedo C, et al.; IBERCovid. Effectiveness of a second dose of an mRNA vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron infection in individuals previously infected by other variants. Clin Infect Dis. 2023;76:e367–e374.
Hulme WJ, Williamson E, Horne EMF, et al. Challenges in estimating the effectiveness of COVID-19 vaccination using observational data. Ann Intern Med. 2023;176:685–693.
Meah S, Shi X, Fritsche LG, et al. Design and analysis heterogeneity in observational studies of COVID-19 booster effectiveness: a review and case study. Sci Adv. 2023;9:eadj3747.
Suissa S, Dell’Aniello S, Renoux C. The prevalent new-user design for studies with no active comparator: the example of statins and cancer. Epidemiology. 2023;34:681–689.
Didelez V, Haug U, Garcia-Albeniz X. Re: Are target trial emulations the gold standard for observational studies? Epidemiology. 2024;35:e3.
Zuo H, Yu L, Campbell SM, Yamamoto SS, Yuan Y. The implementation of target trial emulation for causal inference: a scoping review. J Clin Epidemiol. 2023;162:29–37.
Scola G, Chis Ster A, Bean D, Pareek N, Emsley R, Landau S. Implementation of the trial emulation approach in medical research: a scoping review. BMC Med Res Methodol. 2023;23:186.
Franklin JM, Patorno E, Desai RJ, et al. Emulating randomized clinical trials with nonrandomized real-world evidence studies: first results from the RCT DUPLICATE initiative. Circulation. 2021;143:1002–1013.
Kuma A, Mafune K, Uchino B, Ochiai Y, Enta K, Kato A. Development of chronic kidney disease influenced by serum urate and body mass index based on young-to-middle-aged Japanese men: a propensity score-matched cohort study. BMJ Open. 2022;12:e049540.
Greenland S, Morgenstern H. Matching and efficiency in cohort studies. Am J Epidemiol. 1990;131:151–159.
Westreich D, Cole SR. Invited commentary: positivity in practice. Am J Epidemiol. 2010;171:674–7; discussion 678.
Shiba K, Kawahara T. Using propensity scores for causal inference: pitfalls and tips. J Epidemiol. 2021;31:457–463.
Stuart EA. Matching methods for causal inference: a review and a look forward. Stat Sci. 2010;25:1–21.
Hernán M, Robins J. Causal Inference: What If. Chapman & Hall/CRC; 2020.
Rose S, van der Laan MJ. The open problem. In: van der Laan MJ, Rose S, eds. Targeted Learning: Causal Inference for Observational and Experimental Data. Springer; 2011:3–20.
Keogh RH, Gran JM, Seaman SR, Davies G, Vansteelandt S. Causal inference in survival analysis using longitudinal observational data: sequential trials and marginal structural models. Stat Med. 2023;42:2191–2225.
Dang LE, Balzer LB. Start with the target trial protocol, then follow the roadmap for causal inference. Epidemiology. 2023;34:619–623.
Hernán MA. The hazards of hazard ratios. Epidemiology. 2010;21:13–15.
Hudgens MG, Gilbert PB, Self SG. Endpoints in vaccine trials. Stat Methods Med Res. 2004;13:89–114.
Mehrotra DV, Janes HE, Fleming TR, et al. Clinical endpoints for evaluating efficacy in COVID-19 vaccine trials. Ann Intern Med. 2021;174:221–228.
Dean NE, Halloran ME, Longini IM. Design of vaccine trials during outbreaks with and without a delayed vaccination comparator. Ann Appl Stat. 2018;12:330–347.
Dean NE, Gsell PS, Brookmeyer R, et al. Design of vaccine efficacy trials during public health emergencies. Sci Transl Med. 2019;11:eaat0360.
Hofner B, Asikanius E, Jacquet W, et al. Vaccine development during a pandemic: general lessons for clinical trial design. Stat Biopharm Res. 2024;16:158–170.
Frangakis CE, Rubin DB. Principal stratification in causal inference. Biometrics. 2002;58:21–29.
Lipsitch M, Jha A, Simonsen L. Observational studies and the difficult quest for causality: lessons from vaccine effectiveness and impact studies. Int J Epidemiol. 2016;45:2060–2074.
Fung K, Jones M, Doshi P. Sources of bias in observational studies of COVID-19 vaccine effectiveness. J Eval Clin Pract. 2024;30:30–36.
Vasileiou E, Simpson CR, Shi T, et al. Interim findings from first-dose mass COVID-19 vaccination roll-out and COVID-19 hospital admissions in Scotland: a national prospective cohort study. Lancet. 2021;397:1646–1657.
Lin DY, Gu Y, Wheeler B, et al. Effectiveness of COVID-19 vaccines over a 9-month period in North Carolina. N Engl J Med. 2022;386:933–941.
McConeghy KW, Bardenheier B, Huang AW, et al. Infections, hospitalizations, and deaths among US nursing home residents with vs without a SARS-CoV-2 vaccine booster. JAMA Netw Open. 2022;5:e2245417.
DeMonte JB, Shook-Sa BE, Hudgens MG. Assessing COVID-19 vaccine effectiveness in observational studies via nested trial emulation. arXiv preprint arXiv:2403.18115. 2024. Available at: https://arxiv.org/abs/2403.18115 .
Pearce N, Vandenbroucke JP. Are target trial emulations the gold standard for observational studies? Epidemiology. 2023;34:614–618.
Polinski JM, Weckstein AR, Batech M, et al. Durability of the single-dose Ad26.COV2.S vaccine in the prevention of COVID-19 infections and hospitalizations in the US before and during the delta variant surge. JAMA Netw Open. 2022;5:e222959.
Ioannou GN, Bohnert ASB, O’Hare AM, et al.; COVID-19 Observational Research Collaboratory (CORC). Effectiveness of mRNA COVID-19 vaccine boosters against infection, hospitalization, and death: a target trial emulation in the omicron (B.1.1.529) variant era. Ann Intern Med. 2022;175:1693–1706.
Gazit S, Shlezinger R, Perez G, et al. The incidence of SARS-CoV-2 reinfection in persons with naturally acquired immunity with and without subsequent receipt of a single dose of BNT162b2 vaccine. Ann Intern Med. 2022;175:674–681.
Sjölander A, Greenland S. Ignoring the matching variables in cohort studies – when is it valid and why? Stat Med. 2013;32:4696–4708.
Mansournia MA, Hernán MA, Greenland S. Matched designs and causal diagrams. Int J Epidemiol. 2013;42:860–869.
Rubin DB. Randomization analysis of experimental data: the Fisher randomization test comment. J Am Stat Assoc. 1980;75:591–593.
Harton PE, Chamberlain AT, Moore A, et al. Estimating COVID-19 vaccine effectiveness among children and adolescents using data from a school-based weekly COVID-19 testing program. Vaccine. 2025;61:127292.
Ho DE, Imai K, King G, Stuart EA. Matching as nonparametric preprocessing for reducing model dependence in parametric causal inference. Political Analysis. 2007;15:199–236.
Iacus SM, King G, Porro G. Causal inference without balance checking: coarsened exact matching. Political Analysis. 2012;20:1–24.
Andrillon A, Pirracchio R, Chevret S. Performance of propensity score matching to estimate causal effects in small samples. Stat Methods Med Res. 2020;29:644–658.
Monteiro HS, Lima Neto AS, Kahn R, et al. Impact of CoronaVac on COVID-19 outcomes of elderly adults in a large and socially unequal Brazilian city: a target trial emulation study. Vaccine. 2023;41:5742–5751.
van Eekelen R, Bossuyt PMM, van Geloven N. Time-lag bias induced by unobserved heterogeneity: comparing treated patients to controls with a different start of follow-up. arXiv preprint arXiv:2105.07685. 2024. Available at: https://arxiv.org/abs/2105.07685 .
Hudgens MG, Halloran ME. Toward causal inference with interference. J Am Stat Assoc. 2008;103:832–842.
Halloran ME, Hudgens MG. Dependent happenings: a recent methodological review. Curr Epidemiol Rep. 2016;3:297–305.
Lee Y, Ogburn EL. Network dependence can lead to spurious associations and invalid inference. J Am Stat Assoc. 2021;116:1060–1074.
Zivich PN, Volfovsky A, Moody J, Aiello AE. Assortativity and bias in epidemiologic studies of contagious outcomes: a simulated example in the context of vaccination. Am J Epidemiol. 2021;190:2442–2452.
De-Leon H, Aran D. Over-and under-estimation of vaccine effectiveness. BMC Med Res Methodol. 2025;25:163.
Petersen ML, van der Laan MJ. Causal models and learning from data: integrating causal modeling and statistical estimation. Epidemiology. 2014;25:418–426.
Wu E. nomatch (v0.1.0). Zenodo; 2026. doi: 10.5281/zenodo.19039291.
Contributed Indexing: Keywords: COVID-19; Causal inference; Cohort design; Estimands; Matching; Target trial emulation; Vaccine effectiveness
Substance Nomenclature: 0 (COVID-19 Vaccines)
Entry Date(s): Date Created: 20260330 Date Completed: 20260729 Latest Revision: 20260801
Update Code: 20260801
DOI: 10.1097/EDE.0000000000001982
PMID: 41911278
Βάση Δεδομένων: MEDLINE
Περιγραφή
ISSN:1531-5487
DOI:10.1097/EDE.0000000000001982