scholarly journals Doubly robust adaptive LASSO for effect modifier discovery

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Asma Bahamyirou ◽  
Mireille E. Schnitzer ◽  
Edward H. Kennedy ◽  
Lucie Blais ◽  
Yi Yang
Keyword(s):  
Structural Model ◽  
Inhaled Corticosteroids ◽  
Adaptive Lasso ◽  
Marginal Structural Model ◽  
Treatment Variable ◽  
Effect Modifier ◽  
Robust Adaptive ◽  
Pre Treatment ◽  
Using Data ◽  
Doubly Robust

Abstract Effect modification occurs when the effect of a treatment on an outcome differsaccording to the level of some pre-treatment variable (the effect modifier). Assessing an effect modifier is not a straight-forward task even for a subject matter expert. In this paper, we propose a two-stageprocedure to automatically selecteffect modifying variables in a Marginal Structural Model (MSM) with a single time point exposure based on the two nuisance quantities (the conditionaloutcome expectation and propensity score). We highlight the performance of our proposal in a simulation study. Finally, to illustrate tractability of our proposed methods, we apply them to analyze a set of pregnancy data. We estimate the conditional expected difference in the counterfactual birth weight if all women were exposed to inhaled corticosteroids during pregnancy versus the counterfactual birthweight if all women were not, using data from asthma medications during pregnancy.

Comparing two counterfactual-outcome approaches in causal mediation analysis of a multicategorical exposure: An application for the estimation of the effect of maternal intake of inhaled corticosteroids doses on birthweight

2020 ◽  
Vol 29 (10) ◽  
pp. 2767-2782
Author(s):  
Mariia Samoilenko ◽  
Nadia Arrouf ◽  
Lucie Blais ◽  
Geneviève Lefebvre
Keyword(s):  
Structural Model ◽  
Inhaled Corticosteroids ◽  
Current Knowledge ◽  
Delta Method ◽  
Marginal Structural Model ◽  
Dose Response Relationship ◽  
Model Based ◽  
Causal Mediation ◽  
Exposure Variable ◽  
Causal Mediation Analysis

Although medical research frequently involves an exposure variable with three or more discrete levels, detailed presentations of mediation techniques for dealing with multicategorical (multilevel) exposures are sparse. In this paper, we study two causal mediation approaches applicable to such a type of exposure for continuous mediator and outcome: the closed-form regression-based approach of Valeri and VanderWeele, and the marginal structural model-based approach of Lange, Vansteelandt, and Bekaert. While the consideration of multicategorical exposures is found explicitly addressed in the literature for the latter approach, this is, to our knowledge, not yet the case for the former. We first illustrate the application of the two aforementioned approaches to assess the dose–response relationship between maternal intake of inhaled corticosteroids and birthweight, where this relationship is potentially mediated by gestational age. More specifically, we provide a precise roadmap for the application of the regression-based approach and of the marginal structural model-based approach on our cohort of pregnancies. Expressions for the natural direct and indirect effects associated with our categorical exposure are provided and, for the regression-based approach, analytic formulas for standard error calculation using the delta method are presented for these effects. Second, a simulation study which mimics our data is presented to add to current knowledge on these causal mediation techniques. Results from this study highlight the relevance to assess robustness of mediation results obtained from multicategorical exposures, most notably for the least prevalent of exposure categories.

scholarly journals Experience of Poverty and Problem Sleep in Later Life

2019 ◽  
Vol 41 (7) ◽  
pp. 697-722 ◽  
Author(s):  
Jen-Hao Chen
Keyword(s):  
Older Adults ◽  
Old Age ◽  
Sleep Duration ◽  
Structural Model ◽  
Panel Study ◽  
Later Life ◽  
Marginal Structural Model ◽  
Short Sleep Duration ◽  
Falling Asleep ◽  
Using Data

Older adults are more likely to report problem sleep, but little is known about how the economic challenges of old age affect sleep. Using data from the disability and use of time from the panel study of income dynamics ( N = 1,693), this study applied propensity score methods and the marginal structural model to estimate the associations between exposure to poverty and two measures of problem sleep: risky sleep duration and difficulty falling asleep. Poverty, irrespective of duration of exposure, had little impact on short sleep duration. Exposure to poverty, however, was associated with increased likelihood of long sleep duration on weekends and having difficulty falling asleep on both weekdays and weekends, especially for older adults who were exposed to poverty for 5 or more years. Findings suggest that economic hardship of old age may be a social structural obstacle for healthy sleep.

scholarly journals The association between continuity of care and surgery in lumbar disc herniation patients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eun-San Kim ◽  
Chang-yup Kim
Keyword(s):  
Continuity Of Care ◽  
Disc Herniation ◽  
Structural Model ◽  
Lumbar Disc ◽  
Quality Care ◽  
Target Population ◽  
National Sample ◽  
Marginal Structural Model ◽  
Lumbar Surgery ◽  
High Level

AbstractContinuity of care is a core dimension of high-quality care in the management of disease. The purpose of this study was to investigate the association between continuity of care and lumbar surgery in patients with moderate disc herniation. The Korean National Sample Cohort was used. The target population consisted of patients who have had disc herniation more than 6 months and didn’t get surgery and red flag signs within 6 months from onset. The population was enrolled from 2004 to 2013. The Bice-Boxerman Continuity of Care was used in measuring continuity of care. The marginal structural model with time dependent survival analysis was used. In total, 29,061 patients were enrolled in the cohort. High level of continuity of care was associated with a lower risk of lumbar surgery (HR, 0.27; 95% CI, 0.20–0.27). When the index was calculated only with outpatient visits to primary care with related specialty, the HR was 0.49 (95% CI: 0.43–0.57). In exploratory analysis, patients with lumbar stenosis and spondylolisthesis had higher risk of having a low level of continuity of care. These results indicate that continuity of care is associated with lower rates of lumbar surgery in patients with moderate disc herniation.

Projection Bias in Catalog Orders

2007 ◽  
Vol 97 (4) ◽  
pp. 1217-1249 ◽  
Author(s):  
Michael Conlin ◽  
Ted O'Donoghue ◽  
Timothy J Vogelsang
Keyword(s):  
Field Data ◽  
Structural Model ◽  
Cold Weather ◽  
Change Over Time ◽  
Laboratory Evidence ◽  
Return Probability ◽  
Projection Bias ◽  
Using Data ◽  
Over Time

Evidence suggests that people understand qualitatively how tastes change over time, but underestimate the magnitudes. This evidence is limited, however, to laboratory evidence or surveys of reported happiness. We test for such projection bias in field data. Using data on catalog orders of cold-weather items, we find evidence of projection bias over the weather—specifically, people's decisions are overinfluenced by the current weather. Our estimates suggest that if the order-date temperature declines by 30°F, the return probability increases by 3.95 percent. We also estimate a structural model to measure the magnitude of the bias. (JEL D12, L81)

Using social distancing technology in hotels: a social exchange perspective

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Cristian Morosan ◽  
Agnes DeFranco
Keyword(s):  
Social Exchange ◽  
Health Risks ◽  
Social Exchange Theory ◽  
Structural Model ◽  
Content Type ◽  
Privacy Concerns ◽  
Social Distancing ◽  
Using Data ◽  
Social Rewards

Purpose As social distancing procedures can be facilitated by various hotel technologies, the purpose of this paper is to investigate the extent to which consumers develop perceptions of value regarding the use of certain hotel technologies for social distancing in hotels. Design/methodology/approach Drawing from the social exchange theory, this study conceptualized the benefits of using technologies for social distancing, health risks, social rewards and privacy concerns as antecedents of value of using technologies for social distancing in hotels. The structural model was validated by using data from more than 1,000 nationwide US consumers. Findings Benefits and consumers’ privacy concerns of using technologies for social distancing in hotels were the strongest predictors of value. Social rewards also had a significant but relatively lower effect on value. Health risks was found to have no influence on value. Originality/value The study is the first to examine the role of technologies in mitigating the effects of coronavirus. Thus, it extends the information technology and hospitality literature by examining the role of these technologies in safeguarding individual and public health.

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