scholarly journals Applied causal inference methods for sequential mediators

2021 ◽  
Author(s):  
Maja Popovic ◽  
Lorenzo Richiardi ◽  
Ghislaine Scelo ◽  
Francesca Fasanelli ◽  
Barbara Heude ◽  
...  
Keyword(s):  
Mediation Analysis ◽  
Odds Ratio ◽  
Respiratory Infections ◽  
Probability Weighting ◽  
Inverse Probability ◽  
Causal Pathway ◽  
Inference Methods ◽  
Imputation Approach

Abstract Mediation analysis aims at estimating to what extent the effect of an exposure on an outcome is explained by a set of mediators on the causal pathway between the exposure and the outcome. In this context, the total effect of the exposure on the outcome can be decomposed into the natural indirect effect, i.e. the effect explained by the mediators jointly, and the natural direct effect, i.e. the effect unexplained by the mediators. However finer decompositions are also possible in presence of independent or sequential mediators. As sequential mediation analysis is increasingly common in epidemiology, applied researchers have to interface with difficulties related to the application, implementation, and interpretation of the methods pro- posed in literature. We review four statistical methods to analyse multiple sequential mediators, all based on the counterfactual framework: the inverse odds ratio weight- ing approach, the inverse probability weighting approach, the imputation approach and the extended imputation approach. These approaches are described, compared and implemented using a case-study with the aim to investigate the role of adverse reproductive outcomes and infant respiratory infections on infant wheezing in the Ninfea birth cohort.

scholarly journals Applied causal inference methods for sequential mediators

2021 ◽  
Author(s):  
Daniela Zugna ◽  
Maja Popovic ◽  
Barbara Heude ◽  
Francesca Fasanelli ◽  
Ghislaine Scelo ◽  
...  
Keyword(s):  
Direct Effect ◽  
Indirect Effect ◽  
Odds Ratio ◽  
Respiratory Infections ◽  
Reproductive Outcomes ◽  
Causal Pathway ◽  
Small Joint ◽  
Inference Methods ◽  
Imputation Approach

Abstract Background: Mediation analysis aims at estimating to what extent the effect of an exposure on an outcome is explained by a set of mediators on the causal pathway between the exposure and the outcome. The total effect of the exposure on the outcome can be decomposed into an indirect effect, i.e. the effect explained by the mediators jointly, and a direct effect, i.e. the effect unexplained by the mediators. However finer decompositions are possible in presence of independent or sequential mediators. Methods: We review four statistical methods to analyse multiple sequential mediators , the inverse odds ratio weighting approach, the inverse probability weighting approach, the imputation approach and the extended imputation approach. These approaches are compared and implemented using a case-study with the aim to investigate the role of adverse reproductive outcomes and infant respiratory infections on infant wheezing in the Ninfea birth cohort. Results: Using the inverse odds ratio weighting approach, the direct effect of maternal depression or anxiety in pregnancy is equal to a 59% (95% CI: 27%-94%) increased prevalence of infant wheezing and the mediated effect through adverse reproductive outcomes is equal to a 3% (95% CI:-6%-12%) increased prevalence of infant wheezing. When including infant lower respiratory infections in the mediation pathway, the direct effect decreases to 57% (95% CI: 25%-92%) and the indirect effect increases to 5% (95% CI:-5%,15%). The estimates of the effects obtained using the weighting and the imputation approaches are similar. The extended imputation approach suggests that the small joint indirect effect through adverse reproductive outcomes and lower respiratory infections is due entirely to the contribution of infant lower respiratory infections, independently from the increased prevalence of adverse reproductive outcomes. Conclusions: The use of these methods allows the study of multiple mechanisms underlying the association between an exposure and an outcome and provides a solution for the problem of intermediate confounding by considering the intermediate confounder as a sequential mediator. The choice of the method may depend on what is the effect of main interest, the nature of the variables involved in the analysis and the truthfulness of the underlying assumptions.

scholarly journals Acute flaccid paralysis following enterovirus D68 associated pneumonia, France, 2014

2014 ◽  
Vol 19 (44) ◽  
Author(s):  
M Lang ◽  
A Mirand ◽  
N Savy ◽  
C Henquell ◽  
S Maridet ◽  
...  
Keyword(s):  
United States ◽  
Neurological Disease ◽  
Acute Flaccid Paralysis ◽  
Respiratory Infections ◽  
The United States ◽  
Flaccid Paralysis ◽  
Human Enterovirus ◽  
Enterovirus D68

Human enterovirus D68 (EV-D68) is known to be associated with mild to severe respiratory infections. Recent reports in the United States and Canada of acute flaccid paralysis (AFP) in children with detection of EV-D68 in respiratory samples have raised concerns about the aetiological role of this EV type in severe neurological disease. This case study is the first report of AFP following EV-D68 infection in Europe.

The role of multiplicity in a cult: A case study

1987 ◽  
Author(s):  
William A. Worrall ◽  
Ann W. Stockman

PERAN IBU DALAM PENINGKATAN SISTEM IMUN ANAK DENGAN INFEKSI SALURAN PERNAFASAN AKUT

2019 ◽  
Vol 11 (2) ◽  
pp. 79-86
Author(s):  
Cindy Ayustin Noya ◽  
Angkit Kinasih ◽  
Venti Agustina ◽  
R.Rr Maria Dyah Kurniasari
Keyword(s):  
Immune System ◽  
Acute Respiratory Infection ◽  
Lower Respiratory Tract ◽  
Research Method ◽  
Respiratory Infections ◽  
Acute Respiratory Infections ◽  
Clean Environment ◽  
History Of ◽  
Qualitative Descriptive

Infeksi saluran pernafasan akut atau yang sering disebut ISPA merupakan infeksi pada saluran pernafasan baik saluran pernafasan atas atau bawah.ISPA juga kebanyakan terjadi pada anak balita karena daya tahan tubuh mereka tidak kuat dalam menghadapi penyakit ISPA. ISPA mengakibatkan kematiansekitar15%-20% per tahun pada usia balita di Negara berkembang. Tujuan penelitian ini adalah untuk mengetahui dan menganalisa peran ibu dalam meningkatkan sistem imun anak dengan ISPA.Metode penelitian yang digunakan dalam penelitian ini adalah kualitatif deskriptif dengan sampel purposive sampling.Populasi dan sampel penelitian ini adalah ibu yang mempunyai anak dengan riwayat dan saat ini menderita penyakit ISPA di Batu Gajah Kota Ambon.Partisipan dalam penelitian ini berjumlah 5 orang. Hasil dari penelitian mendapati 4 kategori yaitu pemberian nutrisi pada anak untuk memenuhi kebutuhan agar sistem imunnya terjaga, kebersihan lingkungan, peran ibu dalam melakukan pencegahan pada anaknya yang mengalami ISPA, dan  peran ibu dalam menjaga dan mempertahankan kesehatan anaknya.   Kata kunci: peran ibu, sistem imun, ispa THE ROLE OF MOTHERS IN INCREASING IMMUNE SYSTEM OF CHILDREN WITH ACUTE RESPIRATORY INFECTION    ABSTRACT Acute respiratory infections or often called ARI is an infection of the upper or lower respiratory tract. ARI occurs mostly in children under the age of five because their endurance is not strong in dealing with ARI. ARI results in deaths of around 15%-20% per year at the age of under-five in developing countries. The purpose of this study was to determine and analyze the role of mothers in improving the immune system of children against ARI. The research method used in this study was qualitative descriptive with a purposive sampling sample. Respondents and samples of this study were five mothers who had children with a history of ARI and currently suffering from the disease in Batu Gajah, Ambon City. The results of the study found 4 categories, namely providing nutrition to children to meet their needs so that their immune systems are maintained, clean environment, mother's role in preventing children with ARI, and mother's role to preserve and maintain the health of their children. The findings indicated that in terms of coping or improving the immune system of a child to avoid ARI, it is necessary to have role the of mothers in providing nutrition so that the immune system is boosted, besides that the mother can prevent and protect her child from various diseases, especially ARI. Keywords: role of mothers, immune system, acute respiratory infections

Endangered Butterflies and their Non-Native Host Plants: Examining Shifting Values of Belonging in Restoration

2019 ◽  
Vol 3 (1) ◽  
pp. 1-9
Author(s):  
Robert M. Anderson ◽  
Amy M. Lambert
Keyword(s):  
Ecological Restoration ◽  
Native Species ◽  
Puget Sound ◽  
A Value ◽  
The Social ◽  
Remote Island ◽  
Scientific Truth ◽  
Native Host

The island marble butterfly (Euchloe ausonides insulanus), thought to be extinct throughout the 20th century until re-discovered on a single remote island in Puget Sound in 1998, has become the focus of a concerted protection effort to prevent its extinction. However, efforts to “restore” island marble habitat conflict with efforts to “restore” the prairie ecosystem where it lives, because of the butterfly’s use of a non-native “weedy” host plant. Through a case study of the island marble project, we examine the practice of ecological restoration as the enactment of particular norms that define which species are understood to belong in the place being restored. We contextualize this case study within ongoing debates over the value of “native” species, indicative of deep-seated uncertainties and anxieties about the role of human intervention to alter or manage landscapes and ecosystems, in the time commonly described as the “Anthropocene.” We interpret the question of “what plants and animals belong in a particular place?” as not a question of scientific truth, but a value-laden construct of environmental management in practice, and we argue for deeper reflexivity on the part of environmental scientists and managers about the social values that inform ecological restoration.

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