| 1. |
- Lu, Yunxia, et al.
(författare)
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Anthropometry-based obesity phenotypes and risk of colorectal adenocarcinoma : a large prospective cohort study in Norway
- 2016
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Ingår i: Epidemiology. - Stockholm : Karolinska Institutet, Dept of Molecular Medicine and Surgery. - 1044-3983. ; 27:3, s. 423-432
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: It is unclear whether obesity phenotypes measured by different anthropometric indices are associated with a risk of colorectal adenocarcinoma by anatomical location. METHODS: We compiled harmonized population-based cohort studies (Cohort of Norway, CONOR) with 143,477 participants that were conducted between 1994 and 2010. General, abdominal, and gluteofemoral obesity were assessed by body mass index (BMI, kg/m(2)), waist circumference (cm), and hip circumference (cm). Other measures examined were waist to hip ratio, waist to height ratio, and body adiposity index. We performed Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of obesity relative to a risk of colorectal adenocarcinoma. RESULTS: In total, 2,044 incident cases of colorectal adenocarcinoma were identified. We observed a positive association between waist circumference (high versus low) and adenocarcinoma in the proximal colon (HR = 1.9, 95% CI = 1.5, 2.5) and distal colon (HR = 1.7, 95% CI = 1.3, 2.3) when adjusted for BMI. The association with waist circumference was especially strong in men. BMI was not associated with adenocarcinoma in the colon or rectum after adjusting for waist circumference. We found no association between hip circumference and colorectal adenocarcinoma. When adjusted for BMI plus waist circumference, body adiposity index was negatively associated with adenocarcinoma in the proximal or distal colon. CONCLUSION: Abdominal obesity, but not general or gluteofemoral obesity, was associated with an increased risk of adenocarcinoma in the proximal and the distal colon, especially in men. Muscularity may be negatively associated with risk of colon adenocarcinoma.
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| 2. |
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| 3. |
- Ahlsson, Fredrik, 1967-, et al.
(författare)
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School Performance After Preterm Birth
- 2015
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Ingår i: Epidemiology. - 1044-3983 .- 1531-5487. ; 26:1, s. 106-111
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Tidskriftsartikel (refereegranskat)abstract
- Background: An increased risk of poor school performance for children born preterm has been shown in many studies, but whether this increase is attributable to preterm birth per se or to other factors associated with preterm birth has not been resolved. Methods: We used data from the Swedish Medical Birth Register, the Longitudinal Integration Database for Sickness Insurance and Labor Market Study, the Swedish Multigeneration Register, and the National School Register to link records comprising the Swedish birth cohorts from 1974 through 1991. Linear regression was used to assess the association between gestational duration and school performance, both with and without controlling for parental and socioeconomic factors. In a restricted analysis, we compared siblings only with each other. Results: Preterm birth was strongly and negatively correlated with school performance. The distribution of school grades for children born at 31-33 weeks was on average 3.85 (95% confidence interval = -4.36 to -3.35) centiles lower than for children born at 40 weeks. For births at 22-24 weeks, the corresponding figure was -23.15 (-30.32 to -15.97). When taking confounders into account, the association remained. When restricting the analysis to siblings, however, the association between school performance and preterm birth after week 30 vanished completely, whereas it remained, less pronounced, for preterm birth before 30 weeks of gestation. Conclusions: Our study suggests that the association between school performance and preterm birth after 30 gestational weeks is attributable to factors other than preterm birth per se.
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| 4. |
- Alping, Peter, et al.
(författare)
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Validation of the Swedish Multiple Sclerosis Register Further Improving a Resource for Pharmacoepidemiologic Evaluations
- 2019
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Ingår i: Epidemiology. - : Lippincott Williams & Wilkins. - 1044-3983 .- 1531-5487. ; 30:2, s. 230-233
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish Multiple Sclerosis Register is a national register monitoring treatment and clinical course for all Swedish multiple sclerosis (MS) patients, with high coverage and close integration with the clinic. Despite its great value for epidemiologic research, it has not previously been validated. In this brief report, we summarize a large validation of >3,000 patients in the register using clinical chart review in the context of the COMBAT-MS study. While further improving the data quality for a central cohort of patients available for future epidemiologic research, this study also allowed us to estimate the accuracy and completeness of the register data.
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| 5. |
- Baste, Valborg, et al.
(författare)
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Prospective study of pregnancy outcomes after parental cell phone exposure : the Norwegian mother and child cohort study
- 2015
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Ingår i: Epidemiology. - 1044-3983. ; 26:4, s. 613-621
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Tidskriftsartikel (refereegranskat)abstract
- Background: Research about prenatal exposure to electromagnetic fields from cell phones among expectant parents and reproductive outcome is limited. The aim of this article is to investigate the association between pregnancy outcome and parental cell phone exposure in a large prospective study. Methods: The study was based on the Norwegian Mother and Child Cohort Study conducted during the decade 1999–2009. In that study, pregnant women were recruited before a routine ultrasound examination during gestational week 15; they answered a questionnaire at that time and again around gestational week 30. The expectant father was invited to answer a questionnaire during gestational week 15 (2001–2009). The forms contained questions regarding cell phone use. The response rate was 38.7% and the cohort comprised 100,730 singleton births. Pregnancy outcomes were obtained by linkage to the Medical Birth Registry of Norway. Results: The risk of preeclampsia was slightly lower among women with medium and high cell phone exposure compared with low exposure after adjusting for potential confounders. Fathers with testis exposure when using cell phones had a borderline increased risk of perinatal mortality among offspring and a slightly decreased risk of partner developing preeclampsia during pregnancy compared with no cell phone exposure of head or testis. None of the other pregnancy outcomes was associated with cell phone exposure. Conclusions: We found no association between maternal prenatal or paternal preconceptional cell phone exposure and any of the studied pregnancy outcomes. The only risk estimate suggesting a potential increased risk was not consistent with other findings.
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| 6. |
- Bero Bedada, Getahun, et al.
(författare)
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Short-term Exposure to Ozone and Mortality in Subjects With and Without Previous Cardiovascular Disease
- 2016
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Ingår i: Epidemiology. - 1044-3983 .- 1531-5487. ; 27:5, s. 663-669
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Exposure to ground level ozone (O3) is a public health problem associated with a range of risks across population subgroups. Our aim was to investigate the role of previous cardiovascular diseases (CVDs) in mortality related to short-term O3 exposure.METHODS: Deaths between 1990 and 2010 in Stockholm County were matched with previous hospitalizations in Swedish registries. An urban background monitoring station provided hourly values of air quality data, from which we calculated 8-hour running averages and daily 8-hour maximum. We analyzed associations between daily O3 concentrations and mortality among persons with and without previous CVD hospitalization with a generalized additive model adjusted for time trend, influenza, and weather. We also performed two-pollutant models.RESULTS: There were 302,283 nontrauma-related deaths, out of which 196,916 had previous CVD hospitalization. The mean concentration of daily maximum 8-hour O3 was 62.9 μg/m. An average 10 μg/m increase in the same and preceding day was associated with an increased mortality of 1.72% (95% confidence interval: 0.44%, 3.02%) in those with prior admission for acute myocardial infarction (AMI), which was more than three times higher than for those with no previous AMI (0.50, 95% confidence interval: 0.10%, 0.89%, P value for interaction 0.098). The association between O3 and mortality remained essentially unchanged in two-pollutant models with NO2, NOx, and PM10.CONCLUSIONS: Our study indicates that short-term exposure to O3 is associated with increased mortality in those with a previous hospitalization for AMI.
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| 7. |
- Bijlsma, Maarten J., et al.
(författare)
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The Impact of Unemployment on Antidepressant Purchasing : Adjusting for Unobserved Time-constant Confounding in the g-Formula
- 2019
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Ingår i: Epidemiology. - 1044-3983 .- 1531-5487. ; 30:3, s. 388-395
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Tidskriftsartikel (refereegranskat)abstract
- Background: The estimated effect of unemployment on depression may be biased by time-varying, intermediate, and time-constant confounding. One of the few methods that can account for these sources of bias is the parametric g-formula, but until now this method has required that all relevant confounders be measured.Methods: We combine the g-formula with methods to adjust for unmeasured time-constant confounding. We use this method to estimate how antidepressant purchasing is affected by a hypothetical intervention that provides employment to the unemployed. The analyses are based on an 11% random sample of the Finnish population who were 30–35 years of age in 1995 (n = 49,753) and followed until 2012. We compare estimates that adjust for measured baseline confounders and time-varying socioeconomic covariates (confounders and mediators) with estimates that also include individual-level fixed-effect intercepts.Results: In the empirical data, around 10% of person-years are unemployed. Setting these person-years to employed, the g-formula without individual intercepts found a 5% (95% confidence interval [CI] = 2.5%, 7.4%) reduction in antidepressant purchasing at the population level. However, when also adjusting for individual intercepts, we find no association (−0.1%; 95% CI = −1.8%, 1.5%).Conclusions: The results indicate that the relationship between unemployment and antidepressants is confounded by residual time-constant confounding (selection). However, restrictions on the effective sample when using individual intercepts can compromise the validity of the results. Overall our approach highlights the potential importance of adjusting for unobserved time-constant confounding in epidemiologic studies and demonstrates one way that this can be done.
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| 8. |
- Burgess, Stephen, et al.
(författare)
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Sensitivity Analyses for Robust Causal Inference from Mendelian Randomization Analyses with Multiple Genetic Variants
- 2017
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Ingår i: Epidemiology. - 1044-3983 .- 1531-5487. ; 28:1, s. 30-42
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Forskningsöversikt (refereegranskat)abstract
- Mendelian randomization investigations are becoming more powerful and simpler to perform, due to the increasing size and coverage of genome-wide association studies and the increasing availability of summarized data on genetic associations with risk factors and disease outcomes. However, when using multiple genetic variants from different gene regions in a Mendelian randomization analysis, it is highly implausible that all the genetic variants satisfy the instrumental variable assumptions. This means that a simple instrumental variable analysis alone should not be relied on to give a causal conclusion. In this article, we discuss a range of sensitivity analyses that will either support or question the validity of causal inference from a Mendelian randomization analysis with multiple genetic variants. We focus on sensitivity analyses of greatest practical relevance for ensuring robust causal inferences, and those that can be undertaken using summarized data. Aside from cases in which the justification of the instrumental variable assumptions is supported by strong biological understanding, a Mendelian randomization analysis in which no assessment of the robustness of the findings to violations of the instrumental variable assumptions has been made should be viewed as speculative and incomplete. In particular, Mendelian randomization investigations with large numbers of genetic variants without such sensitivity analyses should be treated with skepticism.
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| 9. |
- Dragano, Nico, et al.
(författare)
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Effort-Reward Imbalance at Work and Incident Coronary Heart Disease A Multicohort Study of 90,164 Individuals
- 2017
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Ingår i: Epidemiology. - : Lippincott Williams & Wilkins. - 1044-3983 .- 1531-5487. ; 28:4, s. 619-626
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Tidskriftsartikel (refereegranskat)abstract
- Background: Epidemiologic evidence for work stress as a risk factor for coronary heart disease is mostly based on a single measure of stressful work known as job strain, a combination of high demands and low job control. We examined whether a complementary stress measure that assesses an imbalance between efforts spent at work and rewards received predicted coronary heart disease.Methods: This multicohort study (the "IPD-Work" consortium) was based on harmonized individual-level data from 11 European prospective cohort studies. Stressful work in 90,164 men and women without coronary heart disease at baseline was assessed by validated effort-reward imbalance and job strain questionnaires. We defined incident coronary heart disease as the first nonfatal myocardial infarction or coronary death. Study-specific estimates were pooled by random effects meta-analysis.Results: At baseline, 31.7% of study members reported effort-reward imbalance at work and 15.9% reported job strain. During a mean follow-up of 9.8 years, 1,078 coronary events were recorded. After adjustment for potential confounders, a hazard ratio of 1.16 (95% confidence interval, 1.00-1.35) was observed for effort-reward imbalance compared with no imbalance. The hazard ratio was 1.16 (1.01-1.34) for having either effort-reward imbalance or job strain and 1.41 (1.12-1.76) for having both these stressors compared to having neither effort-reward imbalance nor job strain.Conclusions: Individuals with effort-reward imbalance at work have an increased risk of coronary heart disease, and this appears to be independent of job strain experienced. These findings support expanding focus beyond just job strain in future research on work stress.
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| 10. |
- Drover, Samantha S. M., et al.
(författare)
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Maternal Thyroid Function During Pregnancy or Neonatal Thyroid Function and Attention Deficit Hyperactivity Disorder : A Systematic Review
- 2019
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Ingår i: Epidemiology. - : Lippincott Williams & Wilkins. - 1044-3983 .- 1531-5487. ; 30:1, s. 130-144
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Forskningsöversikt (refereegranskat)abstract
- BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is the most common neurobehavioral disorder in children, yet its etiology is poorly understood. Early thyroid hormone disruption may contribute to the development of ADHD. Disrupted maternal thyroid hormone function has been associated with adverse neurodevelopmental outcomes in children. Among newborns, early-treated congenital hypothyroidism has been consistently associated with later cognitive deficits.METHODS: We systematically reviewed literature on the association between maternal or neonatal thyroid hormones and ADHD diagnosis or symptoms. We searched Embase, Pubmed, Cinahl, PsycInfo, ERIC, Medline, Scopus, and Web of Science for articles published or available ahead of print as of April 2018.RESULTS: We identified 28 eligible articles: 16 studies of maternal thyroid hormones, seven studies of early-treated congenital hypothyroidism, and five studies of neonatal thyroid hormones. The studies provide moderate evidence for an association between maternal thyroid hormone levels and offspring ADHD, some evidence for an association between early-treated congenital hypothyroidism and ADHD, and little evidence for an association between neonatal thyroid hormone levels and later ADHD.CONCLUSIONS: The reviewed articles suggest an association between maternal thyroid function and ADHD, and possibly between early-treated congenital hypothyroidism and ADHD. Study limitations, however, weaken the conclusions in our systematic review, underlining the need for more research. Importantly, there was much variation in the measurement of thyroid hormone function and of ADHD symptoms. Recommendations for future research include using population-based designs, attending to measurement issues for thyroid hormones and ADHD, considering biologically relevant covariates (e.g., iodine intake), and assessing nonlinear dose responses.
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