Bias due to coarsening of time intervals in the inference for the effectiveness of colorectal cancer screening Journal Article
| Authors: | Karmakar, B.; Zauber, A. G.; Hahn, A. I.; Lau, Y. K.; Doubeni, C. A.; Joffe, M. M. |
| Article Title: | Bias due to coarsening of time intervals in the inference for the effectiveness of colorectal cancer screening |
| Abstract: | Background: Observational studies are frequently used to estimate the comparative effectiveness of different colorectal cancer (CRC) screening methods due to the practical limitations and time needed to conduct large clinical trials. However, time-varying confounders, e.g. polyp detection in the last screening, can bias statistical results. Recently, generalized methods, or G-methods, have been used for the analysis of observational studies of CRC screening, given their ability to account for such time-varying confounders. Discretization, or the process of converting continuous functions into discrete counterparts, is required for G-methods when the treatment and outcomes are assessed at a continuous scale. Development: This paper evaluates the interplay between time-varying confounding and discretization, which can induce bias in assessing screening effectiveness. We investigate this bias in evaluating the effect of different CRC screening methods that differ from each other in typical screening frequency. Application: First, using theory, we establish the direction of the bias. Then, we use simulations of hypothetical settings to study the bias magnitude for varying levels of discretization, frequency of screening and length of the study period. We develop a method to assess possible bias due to coarsening in simulated situations. Conclusions: The proposed method can inform future studies of screening effectiveness, especially for CRC, by determining the choice of interval lengths where data are discretized to minimize bias due to coarsening while balancing computational costs. © 2024 The Author(s); all rights reserved. |
| Keywords: | colorectal cancer; cancer screening; mass screening; time factors; colorectal neoplasms; screening; colorectal tumor; diagnosis; development; epidemiology; observational study; early detection of cancer; attributable risk; bias; comparative effectiveness; time factor; procedures; observational method; detection method; cost analysis; time interval; cancer; humans; human; article; early cancer diagnosis; mortality risk; statistical bias; discretization; directed acyclic graph; observational studies as topic; confounding by indication; g-formula; longitudinal observational study; randomization trial; sequential screening; structured tree graph; confounding factors, epidemiologic; timescale |
| Journal Title: | International Journal of Epidemiology |
| Volume: | 53 |
| Issue: | 4 |
| ISSN: | 0300-5771 |
| Publisher: | Oxford University Press |
| Date Published: | 2024-08-01 |
| Start Page: | dyae096 |
| Language: | English |
| DOI: | 10.1093/ije/dyae096 |
| PUBMED: | 39002174 |
| PROVIDER: | scopus |
| PMCID: | PMC11246168 |
| DOI/URL: | |
| Notes: | Article -- MSK Cancer Center Support Grant (P30 CA008748) acknowledged in PubMed and PDF -- Source: Scopus |
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