Δευτέρα, 5 Αυγούστου 2019

Epidemiology

Sponsorship by Big Oil, Like the Tobacco Industry, Should be Banned by the Research Community
No abstract available

Fine Particulate Air Pollution and Birthweight: Differences in Associations Along the Birthweight Distribution
imageBackground: Maternal exposure to fine particulate air pollution (PM2.5) during pregnancy is associated with lower newborn birthweight, which is a risk factor for chronic disease. Existing studies typically report the average association related with PM2.5 increase, which does not offer information about potentially varying associations at different points of the birthweight distribution. Methods: We retrieved all birth records in Massachusetts between 2001 and 2013 then restricted our analysis to full-term live singletons (n = 775,768). Using the birthdate, gestational age, and residential address reported at time of birth, we estimated the average maternal PM2.5 exposure during pregnancy of each birth. PM2.5 predictions came from a model that incorporates satellite, land use, and meteorologic data. We applied quantile regression to quantify the association between PM2.5 and birthweight at each decile of birthweight, adjusted for individual and neighborhood covariates. We considered effect modification by indicators of individual and neighborhood socioeconomic status (SES). Results: PM2.5 was negatively associated with birthweight. An interquartile range increase in PM2.5 was associated with a 16 g [95% confidence interval (CI) = 13, 19] lower birthweight on average, 19 g (95% CI = 15, 23) lower birthweight at the lowest decile of birthweight, and 14 g (95% CI = 9, 19) lower birthweight at the highest decile. In general, the magnitudes of negative associations were larger at lower deciles. We did not find evidence of effect modification by individual or neighborhood SES. Conclusions: In full-term live births, PM2.5 and birthweight were negatively associated with more severe associations at lower quantiles of birthweight.

Associations Between Ambient Air Pollutant Concentrations and Birth Weight: A Quantile Regression Analysis
imageIntroduction: We investigated the extent to which associations of ambient air pollutant concentrations and birth weight varied across birth weight quantiles. Methods: We analyzed singleton births ≥27 weeks of gestation from 20-county metropolitan Atlanta with conception dates between January 1, 2002 and February 28, 2006 (N = 273,711). Trimester-specific and total pregnancy average concentrations for 10 pollutants, obtained from ground observations that were interpolated using 12-km Community Multiscale Air Quality model outputs, were assigned using maternal residence at delivery. We estimated associations between interquartile range width (IQRw) increases in pollutant concentrations and changes in birth weight using quantile regression. Results: Gestational age-adjusted associations were of greater magnitude at higher percentiles of the birth weight distribution. Pollutants with large vehicle source contributions (carbon monoxide, nitrogen dioxide, PM2.5 elemental carbon, and total PM2.5 mass), as well as PM2.5 sulfate and PM2.5 ammonium, were associated with birth weight decreases for the higher birth weight percentiles. For example, whereas the decrease in mean birthweight per IQRw increase in PM2.5 averaged over pregnancy was -7.8 g (95% confidence interval = −13.6, −2.0 g), the quantile-specific associations were: 10th percentile −2.4 g (−11.5, 6.7 g); 50th percentile −8.9 g (−15.7, −2.0g); and 90th percentile −19.3 g (−30.6, −7.9 g). Associations for the intermediate and high birth weight quantiles were not sensitive to gestational age adjustment. For some pollutants, we saw associations at the lowest quantile (10th percentile) when not adjusting for gestational age. Conclusions: Associations between air pollution and reduced birth weight were of greater magnitude for newborns at relatively heavy birth weights.

Advancing Substantive Knowledge by Asking New Questions, Best Done in the Light of Answers to Older Questions
No abstract available

Increased Risk of Opioid Overdose Death Following Cold Weather: A Case–Crossover Study
imageBackground: The United States is in the midst of an opioid overdose crisis. Little is known about the role of environmental factors in increasing risk of fatal opioid overdose. Methods: We conducted a case–crossover analysis of 3,275 opioid overdose deaths recorded in Connecticut and Rhode Island in 2014–2017. We compared the mean ambient temperature on the day of death, as well as average temperature up to 14 days before death, to referent periods matched on year, month, and day of week. Results: Low average temperatures over the 3–7 days before death were associated with higher odds of fatal opioid overdose. Relative to 11°C, an average temperature of 0°C over the 7 days before death was associated with a 30% higher odds of death (odds ratio: 1.3; 95% confidence interval, 1.1, 1.5). Conclusions: Low average temperature may be associated with higher risk of death due to opioid overdose.

Human Health and the Social Cost of Carbon: A Primer and Call to Action
imageNo abstract available

The Interaction Continuum
imageA common reason given for assessing interaction is to evaluate "whether the effect is larger in one group versus another". It has long been known that the answer to this question is scale dependent: the "effect" may be larger for one subgroup on the difference scale, but smaller on the ratio scale. In this article, we show that if the relative magnitude of effects across subgroups is of interest then there exists an "interaction continuum" that characterizes the nature of these relations. When both main effects are positive then the placement on the continuum depends on the relative magnitude of the probability of the outcome in the doubly exposed group. For high probabilities of the outcome in the doubly exposed group, the interaction may be positive-multiplicative positive-additive, the strongest form of positive interaction on the "interaction continuum". As the probability of the outcome in the doubly exposed group goes down, the form of interaction descends through ranks, of what we will refer to as the following: positive-multiplicative positive-additive, no-multiplicative positive-additive, negative-multiplicative positive-additive, negative-multiplicative zero-additive, negative-multiplicative negative-additive, single pure interaction, single qualitative interaction, single-qualitative single-pure interaction, double qualitative interaction, perfect antagonism, inverted interaction. One can thus place a particular set of outcome probabilities into one of these eleven states on the interaction continuum. Analogous results are also given when both exposures are protective, or when one is protective and one causative. The "interaction continuum" can allow for inquiries as to relative effects sizes, while also acknowledging the scale dependence of the notion of interaction itself.

Bayesian Methods for Exposure Misclassification Adjustment in a Mediation Analysis: Hemoglobin and Malnutrition in the Association Between: Ascaris: and IQ
imageBackground: Soil-transmitted helminth infections have been found to be associated with child development. The objective was to investigate hemoglobin levels and malnutrition as mediators of the association between Ascaris infection and intelligence quotient (IQ) scores in children. Methods: We conducted a longitudinal cohort study in Iquitos, Peru, between September 2011 and July 2016. A total of 1760 children were recruited at 1 year of age and followed up annually to 5 years. We measured Ascaris infection and malnutrition at each study visit, and hemoglobin levels were measured as of age 3. The exposure was defined as the number of detected Ascaris infections between age 1 and 5. We measured IQ scores at age 5 and used Bayesian models to correct exposure misclassification. Results: We included a sample of 781 children in the analysis. In results adjusted for Ascaris misclassification, mean hemoglobin levels mediated the association between Ascaris infection and IQ scores. The natural direct effects (not mediated by hemoglobin) (95% CrI) and natural indirect effects (mediated by hemoglobin) (95% CrI) were compared with no or one infection: −0.9 (−4.6, 2.8) and −4.3 (−6.9, −1.6) for the effect of two infections; −1.4 (−3.8, 1.0) and −1.2 (−2.0, −0.4) for three infections; and −0.4 (−3.2, 2.4) and −2.7 (−4.3, −1.0) for four or five infections. Conclusion: Our results are consistent with the hypothesis that hemoglobin levels mediate the association between Ascaris infection and IQ scores. Additional research investigating the effect of including iron supplements in STH control programs is warranted.

Misclassification of Sex Assigned at Birth in the Behavioral Risk Factor Surveillance System and Transgender Reproductive Health: A Quantitative Bias Analysis
imageBackground: National surveys based on probability sampling methods, such as the Behavioral Risk Factor and Surveillance System (BRFSS), are crucial tools for unbiased estimates of health disparities. In 2014, the BRFSS began offering a module to capture transgender and gender nonconforming identity. Although the BRFSS provides much needed data on the this population, these respondents are vulnerable to misclassification of sex assigned at birth. Methods: We applied quantitative bias analysis to explore the magnitude and direction of the systematic bias present as a result of this misclassification. We use multivariate Poisson regression with robust standard errors to estimate the association between gender and four sex-specific outcomes: prostate-specific antigen testing, Pap testing, hysterectomy, and pregnancy. We applied single and multiple imputation methods, and probabilistic adjustments to explore bias present in these estimates. Results: Combined BRFSS data from 2014, 2015, and 2016 included 1078 transgender women, 701 transgender men, and 450 gender nonconforming individuals. Sex assigned at birth was misclassified among 29.6% of transgender women and 30.2% of transgender men. Transgender and gender nonconforming individuals excluded due to sex-based skip patterns are demographically distinct from those who were asked reproductive health questions, suggesting that there is noteworthy selection bias present in the data. Estimates for gender nonconforming respondents are vulnerable to small degrees of bias, while estimates for cancer screenings among transgender women and men are more robust to moderate degrees of bias. Conclusion: Our results demonstrate that the BRFSS methodology introduces substantial uncertainty into reproductive health measures, which could bias population-based estimates. These findings emphasize the importance of implementing validated sex and gender questions in health surveillance surveys. See video abstract at, http://links.lww.com/EDE/B562.

Prenatal Diethylstilbestrol Exposure and Risk of Depression in Women and Men
imageBackground: Prenatal exposure to diethylstilbestrol (DES), an endocrine-disrupting chemical, may be associated with depression in adulthood, but previous findings are inconsistent. Methods: Women (3,888 DES exposed and 1,729 unexposed) and men (1,021 DES exposed and 1,042 unexposed) participating in the National Cancer Institute (NCI) DES Combined Cohort Follow-up Study were queried in 2011 for any history of depression diagnosis or treatment. Hazard ratios (HRs; 95% confidence intervals [CIs]) estimated the associations between prenatal DES exposure and depression risk. Results: Depression was reported by 993 (26%) exposed and 405 (23%) unexposed women, and 177 (17%) exposed and 181 (17%) unexposed men. Compared with the unexposed, HRs for DES and depression were 1.1 (95% CI = 0.9, 1.2) in women and 1.0 (95% CI = 0.8, 1.2) in men. For medication-treated depression, the HRs (CIs) were 1.1 (0.9, 1.2) in women and 0.9 (0.7, 1.2) in men. In women, the HR (CI) for exposure to a low cumulative DES dose was 1.2 (1.0, 1.4), and for DES exposure before 8 weeks' gestation was 1.2 (1.0, 1.4). In men, the HR for low dose was 1.2 (95% CI = 0.9, 1.6) and there was no association with timing. In women, associations were uninfluenced by the presence of DES-related vaginal epithelial changes or a prior diagnosis of DES-related adverse outcomes. Conclusions: Prenatal DES exposure was not associated overall with risk of depression in women or men. In women, exposure in early gestation or to a low cumulative dose may be weakly associated with an increased depression risk.

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182
6948891480

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