Citation
Coulombe, Janie; Moodie, Erica E. M.; & Platt, Robert W. (2020). Weighted regression analysis to correct for informative monitoring times and confounders in longitudinal studies. Biometrics.Abstract
We address estimation of the marginal effect of a time-varying binary treatment on a continuous longitudinal outcome in the context of observational studies using electronic health records, when the relationship of interest is confounded, mediated and further distorted by an informative visit process. We allow the longitudinal outcome to be recorded only sporadically and assume that its monitoring timing is informed by patients' characteristics. We propose two novel estimators based on linear models for the mean outcome that incorporate an adjustment for confounding and informative monitoring process through generalized inverse probability of treatment weights and a proportional intensity model respectively. We allow for a flexible modelling of the intercept function as a function of time. Our estimators have closed-form solutions, and their asymptotic distributions can be derived. Extensive simulation studies show that both estimators outperform standard methods such as the ordinary least squares estimator or estimators that only account for informative monitoring or confounders. We illustrate our methods using data from the Add Health study, assessing the effect of depressive mood on weight in adolescents. This article is protected by copyright. All rights reservedURL
https://doi.org/10.1111/biom.13285Keyword(s)
Confounding biasReference Type
Journal ArticleJournal Title
BiometricsAuthor(s)
Coulombe, JanieMoodie, Erica E. M.
Platt, Robert W.