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Ferreira Guerra S, Schnitzer ME, Forget A, Blais L. Impact of discretization of the timeline for longitudinal causal inference methods. Stat Med 2020; 39:4069-4085. [PMID: 32875627 DOI: 10.1002/sim.8710] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 07/07/2020] [Accepted: 07/09/2020] [Indexed: 02/06/2023]
Abstract
In longitudinal settings, causal inference methods usually rely on a discretization of the patient timeline that may not reflect the underlying data generation process. This article investigates the estimation of causal parameters under discretized data. It presents the implicit assumptions practitioners make but do not acknowledge when discretizing data to assess longitudinal causal parameters. We illustrate that differences in point estimates under different discretizations are due to the data coarsening resulting in both a modified definition of the parameter of interest and loss of information about time-dependent confounders. We further investigate several tools to advise analysts in selecting a timeline discretization for use with pooled longitudinal targeted maximum likelihood estimation for the estimation of the parameters of a marginal structural model. We use a simulation study to empirically evaluate bias at different discretizations and assess the use of the cross-validated variance as a measure of data support to select a discretization under a chosen data coarsening mechanism. We then apply our approach to a study on the relative effect of alternative asthma treatments during pregnancy on pregnancy duration. The results of the simulation study illustrate how coarsening changes the target parameter of interest as well as how it may create bias due to a lack of appropriate control for time-dependent confounders. We also observe evidence that the cross-validated variance acts well as a measure of support in the data, by being minimized at finer discretizations as the sample size increases.
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Affiliation(s)
- Steve Ferreira Guerra
- Faculté de Pharmacie, Université de Montréal, Montréal, Quebec, Canada.,Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Quebec, Canada
| | - Mireille E Schnitzer
- Faculté de Pharmacie, Université de Montréal, Montréal, Quebec, Canada.,Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Quebec, Canada
| | - Amélie Forget
- Faculté de Pharmacie, Université de Montréal, Montréal, Quebec, Canada.,Research Center, Hôpital du Sacré-Coeur de Montréal, Montréal, Quebec, Canada
| | - Lucie Blais
- Faculté de Pharmacie, Université de Montréal, Montréal, Quebec, Canada.,Research Center, Hôpital du Sacré-Coeur de Montréal, Montréal, Quebec, Canada
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Wey A, Salkowski N, Kremers W, Ahn YS, Snyder J. Piecewise exponential models with time‐varying effects: Estimating mortality after listing for solid organ transplant. Stat (Int Stat Inst) 2020. [DOI: 10.1002/sta4.264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Andrew Wey
- Scientific Registry of Transplant Recipients Hennepin Healthcare Research Institute Minneapolis MN USA
| | - Nicholas Salkowski
- Scientific Registry of Transplant Recipients Hennepin Healthcare Research Institute Minneapolis MN USA
| | - Walter Kremers
- Division of Biomedical Statistics and Informatics Mayo Clinic Rochester MN USA
| | - Yoon Son Ahn
- Scientific Registry of Transplant Recipients Hennepin Healthcare Research Institute Minneapolis MN USA
| | - Jon Snyder
- Scientific Registry of Transplant Recipients Hennepin Healthcare Research Institute Minneapolis MN USA
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French B, Cologne J, Sakata R, Utada M, Preston DL. Selection of reference groups in the Life Span Study of atomic bomb survivors. Eur J Epidemiol 2017; 32:1055-1063. [DOI: 10.1007/s10654-017-0337-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 11/23/2017] [Indexed: 11/24/2022]
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Jensen AKG, Ravn H, Sørup S, Andersen P. A marginal structural model for recurrent events in the presence of time-dependent confounding: non-specific effects of vaccines on child hospitalisations. Stat Med 2016; 35:5051-5069. [PMID: 27582304 DOI: 10.1002/sim.7060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 05/23/2016] [Accepted: 07/01/2016] [Indexed: 11/09/2022]
Abstract
Using a Danish register-based study on childhood vaccination and hospitalisation as motivation, a marginal structural model for recurrent events is studied. The model addresses a number of challenges which may be seen more generally in large register-based cohort studies. One is to adjust for a time-dependent confounder when studying the effect of a time-varying exposure on a recurrent event based on an analysis in continuous time. Another is to report results via a measure which is easy to interpret and communicate even though quite elaborate treatment regimes are considered. Lastly, the implementation of continuously updated weights implies a substantial computationally demanding workload. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Aksel K G Jensen
- Section of Biostatistics, University of Copenhagen. .,Research Center for Vitamins and Vaccines (CVIVA), Bandim Health Project, Statens Serum Institut, Copenhagen, Denmark.
| | - Henrik Ravn
- Research Center for Vitamins and Vaccines (CVIVA), Bandim Health Project, Statens Serum Institut, Copenhagen, Denmark.,OPEN, University of Southern Denmark/Odense University Hospital
| | - Signe Sørup
- Research Center for Vitamins and Vaccines (CVIVA), Bandim Health Project, Statens Serum Institut, Copenhagen, Denmark
| | - Per Andersen
- Section of Biostatistics, University of Copenhagen
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