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Introduction: Left ventricular (LV) diastolic dysfunction and structural abnormalities are common cardiac changes in hypertension (HTN), and several factors other than high blood pressure (BP) may play a role in these changes. The aim of this study was to reveal the relationship between triglyceride glucose (TyG) index, a novel parameter for insulin resistance (IR), with LV diastolic function and structure in hypertensive patients. Material and method: A total of 119 newly diagnosed, untrated hypertensive patients free of diabetes and/or cardiovascular complications were included in this study. IR was estimated with the TyG index calculated from ln [fasting TG (mg/dL) × fasting blood glucose (mg/dL)/2]. Two-dimensional and Doppler echocardiographic examinations were performed to assess LV diastolic functions and structure. Results: Based on median TyG index, 51 patients was assigned as group I (8.7). In patients with high TyG index, left atrial volume index (LAVi) (p .05). Stepwise multiple regression analysis demonstrated that the relationship of TyG index with LV diastolic function and structure was independent of potential confounders (all p

This study empirically illustrates the mechanism by which epidemiological effect measures and statistical evidence can be misleading in the presence of Simpson�s paradox and identify possible alternative methods of analysis to manage the paradox. Three scenarios of observational study designs, including cross-sectional, cohort, and case-control approaches, are simulated. In each scenario, data are generated, and various methods of epidemiological and statistical analyses are undertaken to obtain empirical results that illustrate Simpson�s paradox and mislead conclusions. Rational methods of analysis are also performed to illustrate how to avoid pitfalls and obtain valid results. In the presence of Simpson�s paradox, results from analyses in overall data contradict the findings from all subgroups of the same data. This paradox occurs when distributions of confounding characteristics are unequal in the groups being compared. Data analysis methods which do not take confounding factor into account, including epidemiological 2�2 table analysis, independent samples t-test, Wilcoxon rank-sum test, chi-square test, and univariable regression analysis, cannot manage the problem of Simpson�s paradox and mislead research conclusions. Mantel-Haenszel procedure and multivariable regression methods are examples of rational analysis methods leading to valid results. Therefore, Simpson�s paradox arises as a consequence of extreme unequal distributions of a specific inherent characteristic in groups being compared. Analytical methods which take control of confounding effect must be applied to manage the paradox and obtain valid research evidence regarding the causal association.

Transcriptomic approaches are increasingly used in reproductive medicine to identify candidate endometrial biomarkers. However, it is known that endometrial progression in the molecular biology of the menstrual cycle is a main factor that could affect the discovery of disorder-related genes. Therefore, the aim of this study was to systematically review current practices for considering the menstrual cycle effect and to demonstrate its bias in the identification of potential biomarkers. From the 35 studies meeting the criteria, 31.43% did not register the menstrual cycle phase. We analysed the menstrual cycle effect in 11 papers (including 12 studies) from Gene Expression Omnibus: three evaluating endometriosis, two evaluating recurrent implantation failure, one evaluating recurrent pregnancy loss, one evaluating uterine fibroids and five control studies, which collected endometrial samples throughout menstrual cycle. An average of 44.2% more genes were identified after removing menstrual cycle bias using linear models. This effect was observed even if studies were balanced in the proportion of samples collected at different endometrial stages or only in the mid-secretory phase. Our bias correction method increased the statistical power by retrieving more candidate genes than per-phase independent analyses. Thanks to this practice, we discovered 544 novel candidate genes for eutopic endometriosis, 158 genes for ectopic ovarian endometriosis and 27 genes for recurrent implantation failure. In conclusion, we demonstrate that menstrual cycle progression masks molecular biomarkers, provides new guidelines to unmask them and proposes a new classification that distinguishes between biomarkers of disorder or/and menstrual cycle progression.

Pregnancy and puerperium are typified by marked biobehavioral changes. These changes, which are traceable in both mothers and fathers, play an important role in parenthood and may modulate social cognition abilities. However, the latter effects remain notably unexplored in parents of newborns (PNs). To bridge this gap, we assessed empathy and social emotions (envy and Schadenfreude) in 55 PNs and 60 controls (childless healthy participants without a romantic relationship or sexual intercourse in the previous 48 hours). We used facial electromyography to detect physiological signatures of social emotion processing. Results revealed higher levels of affective empathy and Schadenfreude in PNs, the latter pattern being accompanied by increased activity of the corrugator suppercilii region. These effects were not explained by potential confounding variables (educational level, executive functioning, depression, stress levels, hours of sleep). Our novel findings suggest that PNs might show social cognition changes crucial for parental bonding and newborn care. Fil: Gómez Carvajal, Ana María. Universidad de los Andes; Colombia Fil: Santamaria Garcia, Hernando. Pontificia Universidad Javeriana; Colombia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: García, Adolfo Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; Argentina. Universidad Nacional de Cuyo. Facultad de Educación Elemental y Especial; Argentina. Universidad de San Andrés; Argentina Fil: Valderrama, Mario. Universidad de Los Andes; Venezuela Fil: Mejía, Jhony. Universidad de Los Andes; Venezuela Fil: Santamaría García, José. Pontificia Universidad Javeriana; Colombia Fil: Bernal, Mateo. Pontificia Universidad Javeriana; Colombia Fil: Silva, Jaime. Pontificia Universidad Javeriana; Colombia Fil: Ibañez, Agustin Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; Argentina. Universidad de San Andrés; Argentina. Universidad Autónoma del Caribe; Colombia Fil: Baez, Sandra. Universidad de Los Andes; Venezuela

Occupational health researchers regularly conduct evaluative intervention research for which a randomized controlled trial (RCT) may not be the most appropriate design (eg, effects of policy measures, organizational interventions on work schedules). This article demonstrates the appropriateness of alternative designs for the evaluation of occupational health interventions, which permit causal inferences, formulated along two study design approaches: experimental (stepped-wedge) and observational (propensity scores, instrumental variables, multiple baseline design, interrupted time series, difference-in-difference, and regression discontinuity). For each design, the unique characteristics are presented including the advantages and disadvantages compared to the RCT, illustrated by empirical examples in occupational health. This overview shows that several appropriate alternatives for the RCT design are feasible and available, which may provide sufficiently strong evidence to guide decisions on implementation of interventions in workplaces. Researchers are encouraged to continue exploring these designs and thus contribute to evidence-based occupational health.

Background: We examined the association between opium consumption and pancreatic cancer incidence in a large-scale prospective cohort of the general population in northeastern Iran.Methods: A total of 50,045 adults were systematically followed up (median of 7.4 years), and incident cases of pancreatic cancer were identified. Self-reported data on opium consumption was collected at baseline. Cumulative use (-year) was defined as number of nokhods (a local unit, approximately 0.2 g) of opium consumed per day multiplied by number of years consuming. Adjusted HRs and 95% confidence intervals (CIs) for the association between opium consumption and pancreatic cancer were calculated using Cox proportional hazards regression models.Results: Overall, 54 confirmed cases of pancreatic cancer were identified. Opium use of more than 81 nokhod-years (high cumulative use), compared with never use, was strongly associated with pancreatic cancer even after adjustments for multiple potential confounding factors [HR = 3.01; 95% CI, 1.25–7.26]. High cumulative consumption of opium was significantly associated with risk of pancreatic cancer after adjusting for cumulative dose of cigarette smoking [HR = 3.56; 95% CI, 1.49–8.50]. In a sensitivity analysis, we excluded participants (including 2 pancreatic cancer cases) who were recruited within the first 5 years of starting opium consumption; high cumulative use of opium was still associated with pancreatic cancer risk [HR = 2.75; 95% CI, 1.14–6.64].Conclusions: Our results showed a positive association between opium consumption and pancreatic cancer.Impact: This is the first prospective large-scale study to show the association of opium consumption with pancreatic cancer as a risk factor. Cancer Epidemiol Biomarkers Prev; 27(3); 268–73. ©2017 AACR.

Objective: To examine access to health programs at workplace as a determinant of presenteeism among adults. Methods: Data source was a subsample of the 2009–2010 Canadian Community Health Survey. The outcome was self-reported reduced activities at work (presenteeism). The explanatory variable was self-reported access to a health program at workplace. Logistic regression was used to measure the association between outcome and explanatory variables adjusting for potential confounders. Results: Adjusting for sex, age, education, income, work stress, and chronic conditions, presenteeism was not associated with having access to a health program at workplace (adjusted odds ratio, 1.23; 95% confidence interval, 0.91 to 1.65). The odds of presenteeism were higher in workers who reported high work stress and those with chronic medical conditions. Conclusions: This study found that access to health programs at workplace is not significantly associated with a decline in presenteeism.

Background The case-crossover (CXO) and self-controlled case series (SCCS) designs are increasingly used in pharmacoepidemiology. In both, relative risk estimates are obtained within persons, implicitly controlling for time-fixed confounding variables. Objectives To examine the consistency of relative risk estimates of hip/femur fractures (HFF) associated with the use of benzodiazepines (BZD) across case-only designs in two databases (DBs), when a common protocol was applied. Methods CXO and SCCS studies were conducted in BIFAP (Spain) and CPRD (UK). Exposure to BZD was divided into non-use, current, recent and past use. For CXO, odds ratios (OR; 95%CI) of current use versus non-use/past were estimated using conditional logistic regression adjusted for co-medications (AOR). For the SCCS, conditional Poisson regression was used to estimate incidence rate ratios (IRR; 95%CI) of current use versus non/past-use, adjusted for age. To investigate possible event-exposure dependence the relative risk in the 30 days prior to first BZD exposure was also evaluated. Results In the CXO current use of BZD was associated with an increased risk of HFF in both DBs, AORBIFAP = 1.47 (1.29–1.67) and AORCPRD = 1.55 (1.41–1.70). In the SCCS, IRRs for current exposure was 0.79 (0.72–0.86) in BIFAP and 1.21 (1.13–1.30) in CPRD. However, when we considered separately the 30-day pre-exposure period, the IRR for current period was 1.43 (1.31–1.57) in BIFAP and 1.37 (1.27–1.47) in CPRD. Conclusions CXO designs yielded consistent results across DBs, while initial SCCS analyses did not. Accounting for event-exposure dependence, estimates derived from SCCS were more consistent across DBs and designs. © 2015 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd.

PURPOSE: In observational studies on influenza vaccine effectiveness, confounding variables such as individual chronic diseases often are pooled before inclusion into a multivariable regression model. It has been suggested, however, that the pooling of confounders induces residual confounding, although empirical evidence is scarce. We set out to study the effects of combining several confounders into classes of co-morbidity.METHODS: In a retrospective cohort study on the association between influenza vaccination and mortality, the effect of pooling of 20 individual diagnoses into three dichotomous co-morbidity variables indicating the presence of at least one of a range of diagnoses was studied. The sample size allowed for adjustments for 22 confounders (age, sex, and 20 individual cardiovascular, pulmonary, or oncologic diagnoses).RESULTS: After adjustment forage and sex, further adjustment for 20 separate confounders or the three pooled co-morbidity variables resulted in comparable estimates of influenza vaccine effectiveness: odds ratio 0.78 (95% confidence interval, 0.62-0.98) and odds ratio 0.74 (95% confidence interval, 0.59-0.93), respectively.CONCLUSION: We conclude that pooling of several (related) confounders in influenza vaccine effectiveness studies in health care databases is unlikely to induce important residual confounding. Ann Epidemiol 2009;19:432-436. (c) 2009 Elsevier Inc. All rights reserved.

Objectives: The aim of this study is to examine the role of coping styles in sickness absence. In line with findings that contrast the reactive-passive focused strategies, problem-solving strategies are generally associated with positive results in terms of well-being and overall health outcomes; our hypothesis is that such strategies are positively related to a low frequency of sickness absence and with short lengths (total number of days absent) and durations (mean duration per spell). Methods: Using a prospective design, employees' (N = 3,628) responses on a self-report coping inventory are used to predict future registered sickness absence (i.e. frequency, length, duration, and median time before the onset of a new sick leave period). Results and conclusions: In accordance with our hypothesis, and after adjustment for potential confounders, employees with an active problem-solving coping strategy are less likely to drop out because of sickness absence in terms of frequency, length (longer than 14 days), and duration (more than 7 days) of sickness absence. This positive effect is observed in the case of seeking social support only for the duration of sickness absence and in the case of palliative reaction only for the length and frequency of absence. In contrast, an avoidant coping style, representing a reactive-passive strategy, increases the likelihood of frequent absences significantly, as well as the length and duration of sickness absence. Expression of emotions, representing another reactive-passive strategy, has no effect on future sickness absenteeism. The median time before the onset of a new episode of absenteeism is significantly extended for active problem-solving and reduced for avoidance and for a palliative response. The results of the present study support the notion that problem-solving coping and reactive-passive strategies are inextricably connected to frequency, duration, length and onset of sickness absence. Especially, active problem-solving decreases the chance of future sickness absence. © Springer-Verlag 2007.

Objectives: The aim of this study is to examine the role of coping styles in sickness absence. In line with findings that contrast the reactive-passive focused strategies, problem-solving strategies are generally associated with positive results in terms of well-being and overall health outcomes; our hypothesis is that such strategies are positively related to a low frequency of sickness absence and with short lengths (total number of days absent) and durations (mean duration per spell). Methods: Using a prospective design, employees' (N = 3,628) responses on a self-report coping inventory are used to predict future registered sickness absence (i.e. frequency, length, duration, and median time before the onset of a new sick leave period). Results and conclusions: In accordance with our hypothesis, and after adjustment for potential confounders, employees with an active problem-solving coping strategy are less likely to drop out because of sickness absence in terms of frequency, length (longer than 14 days), and duration (more than 7 days) of sickness absence. This positive effect is observed in the case of seeking social support only for the duration of sickness absence and in the case of palliative reaction only for the length and frequency of absence. In contrast, an avoidant coping style, representing a reactive-passive strategy, increases the likelihood of frequent absences significantly, as well as the length and duration of sickness absence. Expression of emotions, representing another reactive-passive strategy, has no effect on future sickness absenteeism. The median time before the onset of a new episode of absenteeism is significantly extended for active problem-solving and reduced for avoidance and for a palliative response. The results of the present study support the notion that problem-solving coping and reactive-passive strategies are inextricably connected to frequency, duration, length and onset of sickness absence. Especially, active problem-solving decreases the chance of future sickness absence. © Springer-Verlag 2007.