| 1. |
- Almqvist, Catarina, et al.
(författare)
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LifeGene - A large prospective population-based study of global relevance
- 2011
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Ingår i: European Journal of Epidemiology. - Stockholm : Springer Science and Business Media LLC. - 0393-2990 .- 1573-7284. ; 26:1, s. 67-77
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Tidskriftsartikel (refereegranskat)abstract
- Studying gene-environment interactions requires that the amount and quality of the lifestyle data is comparable to what is available for the corresponding genomic data. Sweden has several crucial prerequisites for comprehensive longitudinal biomedical research, such as the personal identity number, the universally available national health care system, continuously updated population and health registries and a scientifically motivated population. LifeGene builds on these strengths to bridge the gap between basic research and clinical applications with particular attention to populations, through a unique design in a research-friendly setting. LifeGene is designed both as a prospective cohort study and an infrastructure with repeated contacts of study participants approximately every 5 years. Index persons aged 18-45 years old will be recruited and invited to include their household members (partner and any children). A comprehensive questionnaire addressing cutting-edge research questions will be administered through the web with short follow-ups annually. Biosamples and physical measurements will also be collected at baseline, and re-administered every 5 years thereafter. Event-based sampling will be a key feature of LifeGene. The household-based design will give the opportunity to involve young couples prior to and during pregnancy, allowing for the first study of children born into cohort with complete pre-and perinatal data from both the mother and father. Questions and sampling schemes will be tailored to the participants' age and life events. The target of LifeGene is to enrol 500,000 Swedes and follow them longitudinally for at least 20 years.
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| 2. |
- Ahlgren, Cecilia, 1946, et al.
(författare)
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A population-based case-control study on viral infections and vaccinations and subsequent multiple sclerosis risk.
- 2009
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Ingår i: European Journal of Epidemiology. - : Springer Science and Business Media LLC. - 1573-7284 .- 0393-2990. ; 24:9, s. 541-52
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Tidskriftsartikel (refereegranskat)abstract
- Viral infections are probably involved in the pathogenesis of multiple sclerosis (MS). A recent cohort study in the Gothenburg population revealed no change in MS incidence associated with the introduction of the Swedish measles, mumps and rubella vaccination programmes. The aim of the present study was to clarify whether these infections or vaccinations, and two other infections, varicella and infectious mononucleosis, influence MS risk. We performed a population-based case-control study in Gothenburg that included 509 MS cases and 2,067 controls, born 1959-1986. Data on infections and vaccinations were obtained from questionnaires and from child health and school health records. We found no significant associations between measles, mumps, rubella or varicella and MS risk. These results were consistent between the two source materials. Infectious mononucleosis was associated with significantly higher MS risk (odds ratio 2.03, 95% CI 1.52-2.73). Overall, there was no significant association between measles-mumps-rubella (MMR) vaccination and MS risk, while those MMR vaccinated before age ten only were at significantly higher MS risk (odds ratio 4.92, 95% CI 1.97-12.20). Those MMR vaccinated both before and after age ten had intermediate MS risk. Infection with measles, mumps, rubella and varicella did not influence MS risk in contrast to infectious mononucleosis which conferred doubled MS risk. The association with 'early' MMR vaccination only was an isolated finding, limited by a small number of subjects and multiple testing. Most likely this was a chance finding. Future studies could investigate it on an a priori basis.
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| 3. |
- Blomgren, K. J., et al.
(författare)
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Interviewer variability - quality aspects in a case-control study
- 2006
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Ingår i: Eur J Epidemiol. - : Springer Science and Business Media LLC. - 0393-2990 .- 1573-7284. ; 21:4, s. 267-77
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Tidskriftsartikel (refereegranskat)abstract
- Quality assurance and quality control are important for the reliability of case-control studies. Here we describe the procedures used in a previously published study, with emphasis on interviewer variability. To evaluate risk factors for acute pancreatitis, information including previous diagnoses and medication was collected from medical records and by telephone interviews from 462 cases and 1781 controls. Quality assurance procedures included education and training of interviewers and data validity checks. Quality control included a classification test, annual test interviews, expert case validation, and database validation. We found pronounced variations between interviewers. The maximal number of interviews per day varied from 3 to 9. The adjusted average (95% CI) number of diagnoses captured per interview of cases was 4.1 (3.8-4.3) and of controls 3.5 (3.4-3.7) (excluding one deviating interviewer). For drugs, the average (95% CI) number per interview was 3.9 (3.7-4.1) for cases and 3.3 (3.2-3.4) for controls (excluding one deviating interviewer). One of the fourteen interviewers deviated significantly from the others, and more so for controls than for cases. This interviewer's data ;were excluded. Nonetheless, data concerning controls more frequently needed correction and supplementation than for cases. Erroneous coding of diagnoses and medication was also more frequent among controls. Thus, a system for quality control of coding practices is crucial. Variability in interviewers' ability to ascertain information is a possible source of bias in interview-based case-control studies when "blinding" cannot be achieved.
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| 4. |
- Boedeker, Wolfgang, et al.
(författare)
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The scientific assessment of combined effects of risk factors - lessons from experimental biosciences for epidemiology?
- 2010
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Ingår i: European Journal of Epidemiology (invited contribution, under review). - : Springer Science and Business Media LLC. - 0393-2990 .- 1573-7284. ; 25:8, s. 539-546
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Tidskriftsartikel (refereegranskat)abstract
- The analysis of combined effects of substances or risk factors has been a subject to science for more than a century. With different goals, combined effect analysis was addressed in almost all experimental biosciences. The major theoretical foundation can be traced back to two distinct origins. First, to the work by the pharmacologist Loewe on the concept of concentration additivity and second to the biometrician Bliss and the concept of independent action. In the search for a general solution and a unified terminology the interrelations of the concepts have extensively been studied and experimental findings reviewed. Meanwhile there seems to be consensus in experimental sciences that each concept has its role in predicting combined effect of agents and both are used for hazard und risk management. In contrast, epidemiologists describe combined effects mainly in terms of interactions in regression models. Although this approach started from a probabilistic model equivalent to the concept of independent action this origin is rarely acknowledged and effect summation is usually the preferred concept nowadays. Obscure biological meaning, the scale dependency of interaction terms as well as unavoidable residual confounding are taken as reasons why no new insights in combined effect analysis are likely to occur from epidemiology. In this paper we sketch the history of ideas and the state of the arts in combined effect analysis. We point to differences and common grounds in experimental biosciences and epidemiology.
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| 5. |
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| 6. |
- Cabrera-Moksnes, Claudia, 1966, et al.
(författare)
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Can the relation between tooth loss and chronic disease be explained by socio-economic status? A 24-year follow-up from the population study of women in Gothenburg, Sweden.
- 2005
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Ingår i: European journal of epidemiology. - : Springer Science and Business Media LLC. - 0393-2990 .- 1573-7284. ; 20:3, s. 229-36
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to evaluate the association between number of missing teeth and all cause, cardiovascular, and cancer mortality as well as morbidity and to explore whether socio-economic factors mediate this association. An ongoing prospective cohort study of 1462 Swedish women included a dental survey in 1968/69 with follow-up until 1992/93. The dental examination included a panoramic radiographic survey and a questionnaire. Number of missing teeth at baseline was analysed in a Cox proportional hazards model to estimate time to mortality and morbidity. Number of missing teeth, independently of socio-economic status variables (the husband's occupational category, combined income, and education) was associated with increased all cause mortality and cardiovascular disease mortality respectively (relative risk (RR): 1.36; 95% confidence interval (95% CI): 1.18-1.58) and (RR: 1.46; 95% CI: 1.15-1.85 per 10 missing teeth), but no associations were found for cancer mortality (RR: 1.18; 95% CI: 0.91-1.52). The relation between poor oral health and future cardiovascular disease could not be explained by measures of socio-economic status in this study.
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| 7. |
- Chauca Strand, Gabriella, 1995, et al.
(författare)
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Impact of organised colorectal cancer screening on age-specific population incidences: evidence from a quasi-experimental study in Sweden
- 2024
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Ingår i: European Journal of Epidemiology. - 0393-2990 .- 1573-7284. ; 39:1, s. 87 - 96
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer (CRC) incurs a significant disease burden globally. Organised CRC screening programmes have been widely implemented for early detection and prevention. To understand the public health impact of these programmes, quantitative evidence of changes in overall and age-specific population incidences is fundamental. We aimed to provide such evidence by exploiting a time lag in the implementation of organised screening in Sweden: two out of 21 regions (these two regions comprise nearly 20% of the total Swedish population) have offered organised screening since 2008; the other regions have offered CRC screening since 2021. Using registry data on diagnosed CRC cases and socio-demographics for all regions in Sweden over the period 1970–2019, Bayesian structural time series modelling and difference-in-differences were applied to analyse the impact of screening on age-specific population incidences over time (CRC cases per 100.000 persons/year). After inviting birth-year cohorts aged 60–69 years for stool-based testing, the incidence rate in the 70–74-year age group decreased significantly over time, with an average reduction of − 44·40 (95% CI − 58·15 to − 31·31) from 2011 to 2019 in the intervention regions. In the overall population aged 60–74 years, there was a net incidence decrease of − 7·99 (95% CI − 13·85 to − 2·39) since the initiation of organised screening in the intervention regions (2008–2019). Organised CRC screening for 60–69-year-olds generated a change in age-specific incidence patterns with a long-lasting incidence decrease in the 70–74-year-old population, implying reductions in the excess mortality and burden of the disease.
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| 8. |
- Chibnik, L. B., et al.
(författare)
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Trends in the incidence of dementia: design and methods in the Alzheimer Cohorts Consortium
- 2017
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Ingår i: European Journal of Epidemiology. - : Springer Science and Business Media LLC. - 0393-2990 .- 1573-7284. ; 32:10, s. 931-938
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have reported a decline in incidence of dementia which may have large implications for the projected burden of disease, and provide important guidance to preventive efforts. However, reports are conflicting or inconclusive with regard to the impact of gender and education with underlying causes of a presumed declining trend remaining largely unidentified. The Alzheimer Cohorts Consortium aggregates data from nine international population-based cohorts to determine changes in the incidence of dementia since 1990. We will employ Poisson regression models to calculate incidence rates in each cohort and Cox proportional hazard regression to compare 5-year cumulative hazards across study-specific epochs. Finally, we will meta-analyse changes per decade across cohorts, and repeat all analysis stratified by sex, education and APOE genotype. In all cohorts combined, there are data on almost 69,000 people at risk of dementia with the range of follow-up years between 2 and 27. The average age at baseline is similar across cohorts ranging between 72 and 77. Uniting a wide range of disease-specific and methodological expertise in research teams, the first analyses within the Alzheimer Cohorts Consortium are underway to tackle outstanding challenges in the assessment of time-trends in dementia occurrence.
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| 9. |
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| 10. |
- Dong, R. C., et al.
(författare)
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Identification of plasma metabolites associated with modifiable risk factors and endophenotypes reflecting Alzheimer's disease pathology
- 2023
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Ingår i: European Journal of Epidemiology. - : Springer Science and Business Media LLC. - 0393-2990 .- 1573-7284.
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Tidskriftsartikel (refereegranskat)abstract
- Modifiable factors can influence the risk for Alzheimer's disease (AD) and serve as targets for intervention; however, the biological mechanisms linking these factors to AD are unknown. This study aims to identify plasma metabolites associated with modifiable factors for AD, including MIND diet, physical activity, smoking, and caffeine intake, and test their association with AD endophenotypes to identify their potential roles in pathophysiological mechanisms. The association between each of the 757 plasma metabolites and four modifiable factors was tested in the wisconsin registry for Alzheimer's prevention cohort of initially cognitively unimpaired, asymptomatic middle-aged adults. After Bonferroni correction, the significant plasma metabolites were tested for association with each of the AD endophenotypes, including twelve cerebrospinal fluid (CSF) biomarkers, reflecting key pathophysiologies for AD, and four cognitive composite scores. Finally, causal mediation analyses were conducted to evaluate possible mediation effects. Analyses were performed using linear mixed-effects regression. A total of 27, 3, 23, and 24 metabolites were associated with MIND diet, physical activity, smoking, and caffeine intake, respectively. Potential mediation effects include beta-cryptoxanthin in the association between MIND diet and preclinical Alzheimer cognitive composite score, hippurate between MIND diet and immediate learning, glutamate between physical activity and CSF neurofilament light, and beta-cryptoxanthin between smoking and immediate learning. Our study identified several plasma metabolites that are associated with modifiable factors. These metabolites can be employed as biomarkers for tracking these factors, and they provide a potential biological pathway of how modifiable factors influence the human body and AD risk.
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