Search results for "Confounding"
showing 10 items of 385 documents
Effects of Heat Waves on Mortality
2013
Heat waves and air pollution are both associated with increased mortality. Their joint effects are less well understood.We explored the role of air pollution in modifying the effects of heat waves on mortality, within the EuroHEAT project. Daily mortality, meteorologic, and air pollution data from nine European cities for the years 1990-2004 were assembled. We defined heat waves by taking both intensity and duration into account. The city-specific effects of heat wave episodes were estimated using generalized estimating equation models, adjusting for potential confounders with and without inclusion of air pollutants (particles, ozone, nitrogen dioxide, sulphur dioxide, carbon monoxide). To …
Hyperhomocysteinemia, obesity and cryptogenic stroke
2011
BACKGROUND: The pathogenic role of hyperhomocysteinemia in cryptogenic stroke is not well established. We aimed to determine homocysteine levels in patients with cryptogenic stroke considering the possible variables that may act as confounders and analyze the influence of obesity on this association. PATIENTS AND METHODS: We conducted a case-control study in 123 patients with cryptogenic stroke aged 42 ± 12 years and in 153 control subjects aged 42 ± 13 years. Serum homocysteine was determined by fluorescence polarization immunoassay. RESULTS: Patients showed statistically higher levels of homocysteine, creatinine and higher BMI than controls (p = 0.045, p = 0.014, p = 0.013), respectively.…
Epoch versus impulse models in the analysis of parametric fMRI studies
2013
Abstract Objective In parametric fMRI studies the relationship between the amplitude of the hemodynamic response and electrophysiological or behavioral parameters is commonly analyzed using the general linear model (GLM). We examined ways of using single-trial response time (RT) in the analysis of a decision-making task to better isolate task-specific activation. Methods fMRI and RT data were recorded in twenty-one subjects performing a visual-oddball-task. Four explanatory variables (EVs) were generated for the GLM-analysis: A conventional (constant impulse) EV, a constant epoch EV informed using subjects’ average RT, a variable impulse EV and a variable epoch EV both informed using single…
The effect of physical activity on long-term income.
2013
Abstract Empirical evidence for the direct effects of physical activities on long-term labor market outcomes is limited. This state of affairs is surprising, because there is a growing amount of support on the positive effects of physical activities on health on the one hand and on the effects of good health on labor market outcomes on the other hand. We examine the long-term income effects of physical activity using a large sample ( N = 5042) of male twins from Finland (Older Finnish Twin Cohort Study, 1975, 1981, 1990), matched to detailed register-based income data (Finnish Longitudinal Employer-Employee Data, 1990–2004). Our primary income measure is calculated over a fifteen-year peri…
Musculoskeletal Pain in Melancholic and Atypical Depression
2016
Objective. Pain and depressive disorders often present together, but little is known about the prevalence of pain in depression subgroups. The objective of this study was to examine the possible differences in the prevalence of musculoskeletal pain between participants in melancholic and atypical depression subgroups. Design. Cross-sectional study. Setting. Depression nurse case managers where depression patients receive treatment in primary health care. Subjects. Participants included 413 depression patients and 401 controls. Methods. Depressive symptoms were determined with the Beck Depression Inventory (BDI-21), and diagnosis of depression was confirmed with the Mini-International Neurop…
Categorizing the Role of Respiration in Cardiovascular and Cerebrovascular Variability Interactions
2022
Objective: Respiration disturbs cardiovascular and cerebrovascular controls but its role is not fully elucidated. Methods: Respiration can be classified as a confounder if its observation reduces the strength of the causal relationship from source to target. Respiration is a suppressor if the opposite situation holds. We prove that a confounding/suppression (C/S) test can be accomplished by evaluating the sign of net redundancy/synergy balance in the predictability framework based on multivariate autoregressive modelling. In addition, we suggest that, under the hypothesis of Gaussian processes, the C/S test can be given in the transfer entropy decomposition framework as well. Experimental p…
Placental metal concentrations and birth outcomes: The Environment and Childhood (INMA) project
2019
To examine the association of placental levels of arsenic (As), cadmium (Cd), mercury (Hg), lead (Pb), manganese (Mn), and chromium (Cr) with birth outcomes (birth weight, length, and head circumference, low birth weight [LBW], gestational age, preterm delivery, and small for gestational age [SGA]) in mother-child pairs from the Environment and Childhood (INMA) Project in Spain.Metal concentrations were measured in placenta tissue samples randomly selected from five INMA cohorts. Data on birth outcomes were obtained from medical records. Associations were assessed in a sub-sample of 327 mother-infant pairs by regression models adjusted for confounding factors and for all metals simultaneous…
A non-randomised trial of an art therapy intervention for patients with haematological malignancies to support post-traumatic growth
2012
The aim of this study was to determine the effect of art therapy on post-traumatic growth in patients with haematological malignancies in a non-randomised trial ( n = 36, intervention group; n = 129, control group). Art therapy was administered over a period of 22 weeks in small groups. Post-traumatic growth was measured with the Stress-Related Growth Scale. After controlling for the effect of potential confounders, no difference in post-traumatic growth was observed between the intervention and control groups after 22 weeks. There was no evidence for an effect of weekly group sessions with art therapy on post-traumatic growth in patients with haematological malignancies.
Straight gyrus morphology in first-episode schizophrenia-spectrum patients
2010
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Diesel motor emissions and lung cancer mortality--results of the second follow-up of a cohort study in potash miners.
2009
International health authorities have graded diesel motor emissions (DME) as probably cancerogenic in human beings. There are gaps in epidemiological evidence regarding exact exposure quantification, confounder control and the investigation of highly exposed populations. We investigated the association of DME ana lung cancer mortality in a historical cohort study of 5,862 German potash miners who were followed from 1970 to 2001. Cumulative exposure (CE) was measured by representative concentrations of total carbon multiplied with exposure years from the mines' medical records. Exposure and smoking behavior were validated by interviews of 3,087 participants. We computed standardized mortalit…