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American Journal of Epidemiology
Journal Prestige (SJR): 2.713
Citation Impact (citeScore): 3
Number of Followers: 202  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0002-9262 - ISSN (Online) 1476-6256
Published by Oxford University Press Homepage  [409 journals]
  • Stress Disorders and Dementia in the Danish Population
    • Authors: Gradus J; Horváth-Puhó E, Lash T, et al.
      Pages: 493 - 499
      Abstract: There is an association between stress and dementia. However, less is known about dementia among persons with varied stress responses and sex differences in these associations. We used this population-based cohort study to examine dementia among persons with a range of clinician-diagnosed stress disorders, as well as the interaction between stress disorders and sex in predicting dementia, in Denmark from 1995 to 2011. This study included Danes aged 40 years or older with a stress disorder diagnosis (n = 47,047) and a matched comparison cohort (n = 232,141) without a stress disorder diagnosis with data from 1995 through 2011. Diagnoses were culled from national registries. We used Cox proportional hazards regression to estimate associations between stress disorders and dementia. Risk of dementia was higher for persons with stress disorders than for persons without such diagnosis; adjusted hazard ratios ranged from 1.6 to 2.8. There was evidence of an interaction between sex and stress disorders in predicting dementia, with a higher rate of dementia among men with stress disorders except posttraumatic stress disorder, for which women had a higher rate. Results support existing evidence of an association between stress and dementia. This study contributes novel information regarding dementia risk across a range of stress responses, and interactions between stress disorders and sex.
      PubDate: Fri, 20 Dec 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy269
      Issue No: Vol. 188, No. 3 (2019)
       
  • Mortality and Cancer Incidence in Carriers of Balanced Robertsonian
           Translocations: A National Cohort Study
    • Authors: Schoemaker M; Jones M, Higgins C, et al.
      Pages: 500 - 508
      Abstract: A balanced robertsonian translocation (rob) results from fusion of 2 acrocentric chromosomes. Carriers are phenotypically normal and are often diagnosed because of recurrent miscarriages, infertility, or aneuploid offspring. Mortality and site-specific cancer risks in carriers have not been prospectively investigated. We followed 1,987 carriers diagnosed in Great Britain for deaths and cancer risk, over an average of 24.1 years. Standardized mortality and incidence ratios were calculated comparing the number of observed events against population rates. Overall mortality was higher for carriers diagnosed before age 15 years (standardized mortality ratio (SMR) = 2.00, 95% confidence interval (CI): 1.09, 3.35), similar for those diagnosed aged 15–44 years (SMR = 1.06, 95% CI: 0.86–1.28), and lower for those diagnosed aged 45–84 years (SMR = 0.81, 95% CI: 0.68, 0.95). Cancer incidence was higher for non-Hodgkin lymphoma (standardized incidence ratio (SIR) = 1.90, 95% CI: 1.01, 3.24) and childhood leukemia (SIR = 14.5, 95% CI: 1.75, 52.2), the latter particularly in rob(15;21) carriers (SIR = 447.8, 95% CI: 11.3, 2,495). Rob(13;14) carriers had a higher breast cancer risk (SIR = 1.58, 95% CI: 1.12, 2.15). Mortality risks relative to the population in diagnosed carriers depend on age at cytogenetic diagnosis, possibly reflecting age-specific cytogenetic referral reasons. Carriers might be at greater risk of childhood leukemia and non-Hodgkin lymphoma and those diagnosed with rob(13;14) of breast cancer.
      PubDate: Sat, 07 Dec 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy266
      Issue No: Vol. 188, No. 3 (2019)
       
  • Shift Work and Respiratory Infections in Health-Care Workers
    • Authors: Loef B; van Baarle D, van der Beek A, et al.
      Pages: 509 - 517
      Abstract: Recently, there has been interest in whether shift work may enhance susceptibility to infection. Our aim was to determine whether shift workers in the health-care field have a higher incidence, duration, and/or severity of influenza-like illness (ILI) and acute respiratory infection (ARI) than non–shift workers. From September 2016 to June 2017, 501 rotating and/or night-shift workers and 88 non–shift workers from the Klokwerk+ Study (the Netherlands, 2016–2017) registered the occurrence of ILI/ARI symptoms daily using a smartphone application. The incidence rate of ILI/ARI (defined as ≥2 symptoms on the same day/≥1 symptom on 2 consecutive days), the mean duration of each episode, and the incidence rate of severe episodes were compared between shift workers and non–shift workers using negative binomial regression and linear mixed-model analysis. In total, participants completed 110,347 diaries. Shift workers’ incidence rate of ILI/ARI was 1.20 (95% confidence interval (CI): 1.01, 1.43) times higher than that of non–shift workers, and for severe ILI/ARI episodes, shift workers’ incidence rate was 1.22 (95% CI: 1.01, 1.49) times higher. The mean duration of an ILI/ARI episode did not differ (ratio between means = 1.02, 95% CI: 0.87, 1.19). In conclusion, shift workers in health care had more ILI/ARI episodes and more severe ILI/ARI episodes than non–shift workers, but with a similar duration. Insight into underlying mechanisms connecting shift work and infection susceptibility will contribute to the design of preventive initiatives.
      PubDate: Tue, 26 Nov 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy258
      Issue No: Vol. 188, No. 3 (2019)
       
  • Associations Between Features of Placental Morphology and Birth Weight in
           Dichorionic Twins
    • Authors: Freedman A; Hogue C, Marsit C, et al.
      Pages: 518 - 526
      Abstract: Low birth weight is associated with perinatal and long-term morbidity and mortality, and may be a result of abnormal placental development and function. In studies of singletons, associations have been reported between features of placental morphology and birth weight. Evaluating similar associations within twin pairs offers a unique opportunity to control for key confounders shared within a twin pair, including gestational age, parental characteristics, and intrauterine environment. Data from 3 studies in the United States that were completed from 2012 to 2013, 2006 to 2008, and 1959 to 1966 were used in our analysis of 208 sets of dichorionic twins with unfused placentas. We used linear regression to model difference in birth weight within a twin pair as a function of differences in placental characteristics (i.e., thickness, 2-dimensional surface area, intraplacental difference in diameter). After controlling for sex discordance, a 75.3- cm2 difference in placental surface area, which reflects the interquartile range, was associated with a difference in birth weight of 142.1 g (95% confidence interval (CI): 62.9, 221.3). The magnitude of the association also may be larger for same-sex male pairs than same-sex female pairs (males: 265.8 g, 95% CI: 60.8, 470.8; females: 133.0 g, 95% CI: 15.7, 250.3). Strong associations between surface area and birth weight are consistent with reported results for singleton pregnancies.
      PubDate: Tue, 19 Nov 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy255
      Issue No: Vol. 188, No. 3 (2019)
       
  • Comparison of the Associations of Early-Life Factors on Wheezing
           Phenotypes in Preterm-Born Children and Term-Born Children
    • Authors: Kotecha S; Watkins W, Lowe J, et al.
      Pages: 527 - 536
      Abstract: Although respiratory symptoms, including wheezing, are common in preterm-born subjects, the natural history of the wheezing phenotypes and the influence of early-life factors and characteristics on phenotypes are unclear. Participants from the Millennium Cohort Study who were born between 2000 and 2002 were studied at 9 months and at 3, 5, 7, and 11 years. We used data-driven methods to define wheezing phenotypes in preterm-born children and investigated whether the association of early-life factors and characteristics with wheezing phenotypes was similar between preterm- and term-born children. A total of 1,049/1,502 (70%) preterm-born children and 12,307/17,063 (72%) term-born children had recent wheeze data for 3 or 4 time points. Recent wheeze was more common at all time points in the preterm-born group than in term-born group. Four wheezing phenotypes were defined for both groups: no/infrequent, early, persistent, and late. Early-life factors and characteristics, especially antenatal maternal smoking, atopy, and male sex, were associated with increased rates for all phenotypes in both groups, and breastfeeding was protective in both groups, except late wheeze in the preterm group. Preterm-born children had similar phenotypes to term-born children. Although early-life factors and characteristics were similarly associated with the wheezing phenotypes in both groups, the preterm-born group had higher rates of early and persistent wheeze. However, a large proportion of preterm-born children had early wheeze that resolved with time.
      PubDate: Tue, 22 Jan 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy268
      Issue No: Vol. 188, No. 3 (2019)
       
  • Potential Effects on Mortality of Replacing Sedentary Time With Short
           Sedentary Bouts or Physical Activity: A National Cohort Study
    • Authors: Diaz K; Duran A, Colabianchi N, et al.
      Pages: 537 - 544
      Abstract: Little is known concerning the type of activity that should be substituted for sedentary time and its potentially most hazardous form (prolonged sedentary bouts) to impart health benefit. We used isotemporal substitution techniques to examine whether 1) replacing total sedentary time with light-intensity or moderate to vigorous physical activity (LIPA or MVPA) or 2) replacing prolonged sedentary bouts with shorter sedentary bouts is associated with reductions in all-cause mortality risk. Participants (n = 7,999) from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a national cohort of US adults aged ≥45 years, were studied. Sedentary time was measured by accelerometry between 2009 and 2013. There was a beneficial association with mortality risk for replacing total sedentary time with both LIPA (per 30 minutes, hazard ratio (HR) = 0.83; 95% confidence interval (CI): 0.80, 0.87) and MVPA (per 30 minutes, HR = 0.65; 95% CI: 0.50, 0.85). Similarly, there was a beneficial association for replacing prolonged sedentary-bout time with LIPA and MVPA but not for replacement with shorter sedentary bouts (per 30 minutes, HR = 1.00; 95% CI: 0.96, 1.03). These findings suggest short sedentary bouts still carry mortality risk and are not a healthful alternative to prolonged sedentary bouts. Instead, physical activity of any intensity is needed to mitigate the mortality risks incurred by sedentary time.
      PubDate: Mon, 14 Jan 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy271
      Issue No: Vol. 188, No. 3 (2019)
       
  • The Impact of Screening and Partner Notification on Chlamydia Prevalence
           and Numbers of Infections Averted in the United States, 2000–2015:
           Evaluation of Epidemiologic Trends Using a Pair-Formation Transmission
           Model
    • Authors: Rönn M; Tuite A, Menzies N, et al.
      Pages: 545 - 554
      Abstract: Population-level effects of control strategies on the dynamics of Chlamydia trachomatis transmission are difficult to quantify. In this study, we calibrated a novel sex- and age-stratified pair-formation transmission model of chlamydial infection to epidemiologic data in the United States for 2000–2015. We used sex- and age-specific prevalence estimates from the National Health and Nutrition Examination Surveys, case report data from national chlamydia surveillance, and survey data from the Youth Risk Behavior Survey on the proportion of the sexually active population aged 15–18 years. We were able to reconcile national prevalence estimates and case report data by allowing for changes over time in screening coverage and reporting completeness. In retrospective analysis, chlamydia prevalence was estimated to be almost twice the current levels in the absence of screening and partner notification. Although chlamydia screening and partner notification were both found to reduce chlamydia burden, the relative magnitude of their estimated impacts varied in our sensitivity analyses. The variation in the model predictions highlights the need for further data collection and research to improve our understanding of the natural history of chlamydia and the pathways through which prevention strategies affect transmission dynamics.
      PubDate: Fri, 04 Jan 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy272
      Issue No: Vol. 188, No. 3 (2019)
       
  • Evaluation of the Performance of Algorithms That Use Serial Hepatitis C
           RNA Tests to Predict Treatment Initiation and Sustained Virological
           Response Among Patients Infected With Hepatitis C Virus
    • Authors: Osinubi A; Harris A, Vellozzi C, et al.
      Pages: 555 - 561
      Abstract: The structure of electronic medical record data prevents easy population-level monitoring of hepatitis C virus (HCV) treatment uptake and cure. Using an HCV registry from a public hospital system in Atlanta, Georgia, we developed multiple algorithms that use serial HCV RNA test results as proxy measures for initiation of direct-acting antiviral (DAA) treatment and sustained virological response (SVR). We calculated sensitivity and positive predictive values (PPVs) by comparing the algorithms with the DAA initiation and SVR results from the registry. From December 2013 to August 2016, 1,807 persons actively infected with HCV were identified in the registry. Of those, 698 initiated DAA treatment on the basis of medical record abstraction; of 442 patients with treatment start and/or end dates, 314 had documented SVR. Treatment algorithm 2 (a detectable HCV RNA result followed by 2 sequential HCV RNA test results) and treatment algorithm 5 (a detectable HCV RNA result followed by 2 sequential HCV RNA test results >6 weeks apart) had the highest sensitivity (87% and 85%, respectively) and PPV (80% and 82%, respectively) combinations. Four SVR algorithms relied on fulfilling treatment algorithm definitions and having an undetectable HCV RNA test result ≥12 weeks after the last HCV RNA result; sensitivity for all 4 algorithms was 79%, and PPV was 92%–93%. Algorithms using serial quantitative HCV RNA results can serve as proxy measures for evaluating population-level DAA treatment and SVR outcomes.
      PubDate: Sat, 07 Dec 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy270
      Issue No: Vol. 188, No. 3 (2019)
       
  • Structure and Control of Healthy Worker Effects in Studies of Pregnancy
           Outcomes
    • Authors: Johnson C; Rocheleau C, Grajewski B, et al.
      Pages: 562 - 569
      Abstract: Much of the literature on the healthy worker effect focuses on studies of chronic disease and mortality; however, when studying pregnancy outcomes, these effects might differ because of the short, defined risk periods of most pregnancy outcomes. Three pregnancy-specific healthy worker effects have also been described, but the structure of these effects has not yet been investigated when occupational exposure, and not employment status, is the exposure of interest. We used directed acyclic graphs to examine healthy worker effects in studies of occupational exposures and pregnancy outcomes: the healthy hire effect, the healthy worker survivor effect, the desperation/privilege effect (differential workforce reentry after pregnancy), the reproductively unhealthy worker effect (women with live births leave the workforce, while women with nonlive births do not), and the insecure pregnancy effect (women with adverse pregnancy outcomes reduce their exposures in subsequent pregnancies). Given our assumptions, we conclude that the healthy hire effect, the desperation/privilege effect, the reproductively unhealthy worker effect, and the insecure pregnancy effect result from confounding that can be addressed if data on measured confounders, such as employment status, are available. The presence of the healthy worker survivor effect, however, varies by study design. Different types of healthy worker effects can be present in studies of occupational exposure and pregnancy outcomes, and many of them are easily addressed analytically.
      PubDate: Sat, 21 Dec 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy277
      Issue No: Vol. 188, No. 3 (2019)
       
  • Gestational Age at Arrest of Development: An Alternative Approach for
           Assigning Time at Risk in Studies of Time-Varying Exposures and
           Miscarriage
    • Authors: Sundermann A; Mukherjee S, Wu P, et al.
      Pages: 570 - 578
      Abstract: The time between arrest of pregnancy development and miscarriage represents a window in which the pregnancy is nonviable and not developing. In effect, the pregnancy loss has already occurred, and additional exposure cannot influence its outcome. However, epidemiologic studies of miscarriage traditionally use gestational age at miscarriage (GAM) to assign time in survival analyses, which overestimates duration of exposure and time at risk. In Right From the Start, a pregnancy cohort study (2000–2012), we characterized the gap between estimated gestational age at arrest of development (GAAD) and miscarriage using transvaginal ultrasound in 500 women recruited from 3 states (North Carolina, Tennessee, and Texas). We compared effect estimates from models using GAAD with GAM to assign time at risk through a simulation study of several exposure patterns with varying effect sizes. The median gap between GAAD and miscarriage was 23 days (interquartile range, 15–32). Use of GAAD decreased the bias and variance of the estimated association for time-varying exposures, whereas half the time using GAM led to estimates that differed from the true effect by more than 20%. Using GAAD to assign time at risk should result in more accurate and consistent characterization of miscarriage risk associated with time-varying exposures.
      PubDate: Fri, 06 Dec 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy267
      Issue No: Vol. 188, No. 3 (2019)
       
  • Guideline-Based Physical Activity and Survival Among US Men With
           Nonmetastatic Prostate Cancer
    • Authors: Dickerman B; Giovannucci E, Pernar C, et al.
      Pages: 579 - 586
      Abstract: The survival impact of adhering to current physical activity guidelines after prostate cancer diagnosis is unknown. We therefore emulated a target trial of guideline-based physical activity interventions and 10-year survival among US men with nonmetastatic prostate cancer. We used observational data on 2,299 men in the Health Professionals Follow-up Study who were diagnosed with nonmetastatic prostate cancer from 1998 to 2010 and were free of conditions that might have precluded participation at baseline (first postdiagnostic questionnaire). We estimated their survival under several guideline-based physical activity interventions starting at baseline and ending at the development of conditions limiting physical ability. We adjusted for baseline and time-varying risk factors for death using the parametric g-formula. Compared with the observed 15.4% mortality risk, the estimated 10-year risks of mortality were 13.0% (95% confidence interval (CI): 10.9, 15.4) and 11.1% (95% CI: 8.7, 14.1) for ≥1.25 hours/week and ≥2.5 hours/week of vigorous activity, respectively, and 13.9% (95% CI: 12.0, 16.0) and 12.6% (95% CI: 10.6, 14.7) for ≥2.5 hours/week and ≥5 hours/week of moderate activity, respectively. We estimated that these men would have experienced clinically meaningful reductions in mortality had they followed current physical activity recommendations until the development of conditions limiting physical ability. These findings may help guide clinical recommendations for prostate cancer patients and the design of future randomized trials.
      PubDate: Fri, 29 Nov 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy261
      Issue No: Vol. 188, No. 3 (2019)
       
  • An Investigation of Selection Bias in Estimating Racial Disparity in
           Stroke Risk FactorsThe REGARDS Study
    • Authors: Long D; Howard G, Long D, et al.
      Pages: 587 - 597
      Abstract: Selection due to survival or attrition might bias estimates of racial disparities in health, but few studies quantify the likely magnitude of such bias. In a large national cohort with moderate loss to follow-up, we contrasted racial differences in 2 stroke risk factors, incident hypertension and incident left ventricular hypertrophy, estimated by complete-case analyses, inverse probability of attrition weighting, and the survivor average causal effect. We used data on 12,497 black and 17,660 white participants enrolled in the United States (2003–2007) and collected incident risk factor data approximately 10 years after baseline. At follow-up, 21.0% of white participants and 23.0% of black participants had died; additionally 22.0% of white participants and 28.4% of black participants had withdrawn. Individual probabilities of completing the follow-up visit were estimated using baseline demographic and health characteristics. Adjusted risk ratio estimates of racial disparities from complete-case analyses in both incident hypertension (1.11, 95% confidence interval: 1.02, 1.21) and incident left ventricular hypertrophy (1.02, 95% confidence interval: 0.84, 1.24) were virtually identical to estimates from inverse probability of attrition weighting and survivor average causal effect. Despite racial differences in mortality and attrition, we found little evidence of selection bias in the estimation of racial differences for these incident risk factors.
      PubDate: Tue, 19 Nov 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy253
      Issue No: Vol. 188, No. 3 (2019)
       
  • Causal Mediation Analysis With Observational Data: Considerations and
           Illustration Examining Mechanisms Linking Neighborhood Poverty to
           Adolescent Substance Use
    • Authors: Rudolph K; Goin D, Paksarian D, et al.
      Pages: 598 - 608
      Abstract: Understanding the mediation mechanisms by which an exposure or intervention affects an outcome can provide a look into what has been called a “black box” of many epidemiologic associations, thereby providing further evidence of a relationship and possible points of intervention. Rapid methodologic developments in mediation analyses mean that there are a growing number of approaches for researchers to consider, each with its own set of assumptions, advantages, and disadvantages. This has understandably resulted in some confusion among applied researchers. Here, we provide a brief overview of the mediation methods available and discuss points for consideration when choosing a method. We provide an in-depth explication of 2 of the many potential estimators for illustrative purposes: the Baron and Kenny mediation approach, because it is the most commonly used, and a recently developed approach for estimating stochastic direct and indirect effects, because it relies on far fewer assumptions. We illustrate the decision process and analytical procedure by estimating potential school- and peer-based mechanisms linking neighborhood poverty to adolescent substance use in the National Comorbidity Survey Adolescent Supplement.
      PubDate: Wed, 18 Dec 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy248
      Issue No: Vol. 188, No. 3 (2019)
       
  • Multinomial Extension of Propensity Score Trimming Methods: A Simulation
           Study
    • Authors: Yoshida K; Solomon D, Haneuse S, et al.
      Pages: 609 - 616
      Abstract: Crump et al. (Biometrika. 2009;96(1):187–199), Stürmer et al. (Am J Epidemiol. 2010;172(7):843–854), and Walker et al. (Comp Eff Res. 2013;2013(3):11–20) proposed propensity score (PS) trimming methods as a means to improve efficiency (Crump) or reduce confounding (Stürmer and Walker). We generalized the trimming definitions by considering multinomial PSs, one for each treatment, and proved that these proposed definitions reduce to the original binary definitions when we have only 2 treatment groups. We then examined the performance of the proposed multinomial trimming methods in the setting of 3 treatment groups, in which subjects with extreme PSs more likely had unmeasured confounders. Inverse probability of treatment weights, matching weights, and overlap weights were used to control for measured confounders. All 3 methods reduced bias regardless of the weighting methods in most scenarios. Multinomial Stürmer and Walker trimming were more successful in bias reduction when the 3 treatment groups had very different sizes (10:10:80). Variance reduction, seen in all methods with inverse probability of treatment weights but not with matching weights or overlap weights, was more successful with multinomial Crump and Stürmer trimming. In conclusion, our proposed definitions of multinomial PS trimming methods were beneficial within our simulation settings that focused on the influence of unmeasured confounders.
      PubDate: Thu, 05 Dec 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy263
      Issue No: Vol. 188, No. 3 (2019)
       
  • SOME DESIRABLE PROPERTIES OF THE BONFERRONI CORRECTION: IS THE BONFERRONI
           CORRECTION REALLY SO BAD'
    • Authors: VanderWeele T; Mathur M.
      Pages: 617 - 618
      PubDate: Tue, 19 Nov 2019 00:00:00 GMT
      DOI: 10.1093/aje/kwy250
      Issue No: Vol. 188, No. 3 (2019)
       
 
 
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