1. |
- Lager, Anton C. J., et al.
(författare)
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Cognitive and emotional outcomes after prolonged education : a quasi-experiment on 320 182 Swedish boys
- 2017
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Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 0300-5771 .- 1464-3685. ; 46:1, s. 303-311
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cognitive and socio-emotional abilities are powerful predictors of death and disease as well as of social and economic outcomes. Education is societies' main way of promoting these abilities, ideally so that inequalities by socioeconomic background are reduced. However, the extent to which education serves these cognitive, social-emotional and equality objectives is relatively unknown and intensively debated. Drawing on a Swedish school reform that was explicitly designed as a massive quasiexperiment, we assessed differential impact of education on intelligence and emotional control across childhood socioeconomic position. We also assessed initial differences in abilities by childhood socioeconomic position and how well childhood socioeconomic position and abilities predict all-cause mortality. Methods: The Swedish comprehensive school reform, rolled out during the 1950s, extended compulsory education from 8 to 9 years in some municipalities whereas others were kept as controls for the sake of evaluation. We followed eight full cohorts of Swedish boys born between 1951 and 1958, who lived in 1017 municipalities with known experimental status (344 336 boys) and whose childhood socioeconomic position was known (320 182 boys). At conscription, intelligence was measured by four subtests and emotional control (calm and efficient responses in various situations) was rated by a military psychologist. Both measures were standardized to have a mean of 100 and standard deviation of 15. All-cause mortality was recorded until 49-56 years of age. Results: The reform had an average positive impact on intelligence of 0.75 IQ units (95% confidence interval (CI): 0.54, 0.97; P < 0.0005). The impact on emotional control was negative; -0.50 units (95% CI: -0.72, -0.28; P < 0.0005). Both effects differed by socioeconomic background so that the average IQ difference between sons of high nonmanual and unqualified manual workers was reduced from 16.32 to 15.57 units and the difference in emotional control was reduced from 6.50 to 5.63 units. All-cause mortality was predicted by low childhood socioeconomic position [hazard ratio (HR) = 1.15 [95% CI: 1.11, 1.20], P < 0.0005], low intelligence [HR = 1.39 (95% CI: 1.34, 1.44), P < 0.0005] as well as low emotional control [HR = 1.61 (95% CI: 1.55, 1.67), P < 0.0005] in mutually adjusted models. Conclusions: Extending compulsory education promoted intelligence but lowered emotional control, and reduced disparities over social background in both. Emotional control was the strongest predictor of all-cause mortality. Our results are in line with the idea that education is important in our efforts to achieve healthy, competent and fair societies, but much more work is needed to understand the links between education and non-cognitive skills.
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2. |
- Seblova, Dominika
(författare)
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Causal effects of education on cognition : how do we generate evidence?
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Education is a key institution in our societies, and should prepare us for future by improving cognition and teaching us needed life skills. Education is associated with many aspects of life, including health. For example, there is hope that improved education may help to reduce the burden of dementia, which is a large public health challenge for which treatment is missing. However, such hopes assume causality of the relationship between education and dementia. Aim: The primary aim of this doctoral thesis was to examine the relationship between formal education and cognition (i.e. early-life cognition, cognitive decline and neuropathological disturbances to cognition in form of dementia) during the life-course. The secondary aim was to discuss how we can generate evidence on causal relationships and infer causation in epidemiology. Methods: This thesis adopted a plurality and triangulation of evidence approach with regards to arriving at causal conclusions. The individual studies employed diverse designs in the exploration of links between education, cognition and dementia. Study I described thirty-year trends in the burden of dementia in inpatient records according to educational level. In Study II, we exploited a quasi-experimental comprehensive school reform in order to ascertain causal relationship between education and intelligence in men at military conscription. Further, we explored the heterogeneity of the effect according to childhood socioeconomic position. Study III focused on dementia. In order to investigate the causal effect of education on dementia diagnosis in Swedish registers, we used a primary schooling reform as a natural experiment. The reform had minimal spill-over effects on adult socioeconomic factors. The last study (Study IV) was a systematic review and meta-analysis summarizing the evidence from population-based studies of healthy adults. It examined the association between education and change in episodic memory, a cognitive domain with strong links to dementia. Results: The burden of dementia in Swedish inpatient records began to decline during the last half a decade. Educational inequalities in dementia incidence remained stable and those with the highest educational attainment had the lowest dementia incidence rates. The comprehensive school reform increased intelligence and reduced socioeconomic disparities in cognition. However, in Study III we did not discover any substantial effect of the primary schooling reform on dementia risk. Similarly, the meta-analytic estimate indicated that the association between education and age-related decline in episodic memory is negligible. Conclusions: Education is associated with level of cognition, but not decline - at least not in the episodic memory domain. Further, prolonged education cannot be uncritically assumed to reduce dementia burden, especially in absence of spillover effects to adult socioeconomic factors. However, education fulfils one of its many aims by increasing early-life cognition, and also has the potential to reduce socioeconomic inequalities in cognitive ability.
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3. |
- Seblova, Dominika, et al.
(författare)
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Changes in Cognitive Impairment in the Czech Republic
- 2019
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 72:3, s. 693-701
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Tidskriftsartikel (refereegranskat)abstract
- Background: Studies from North America and Western Europe suggest stable or declining trends in impaired cognition across birth cohorts. Objective: We aimed to examine changes in the age-specific prevalence of cognitive impairment in the Czech Republic. Methods: The study used two samples from the population-based Czech Survey on Health, Ageing and Retirement in Europe. Age-specific prevalence of cognitive impairment (defined based on scores in verbal fluency, immediate recall, delayed recall, and temporal orientation) was compared between participants in wave 2 (2006/2007; n = 1,107) and wave 6 (2015; n = 3,104). Logistic regression was used to estimate the association between the wave and cognitive impairment, step-wise adjusting for sociodemographic and clinical characteristics. Multiple sensitivity analyses, focusing on alternative operationalizations of relative cognitive impairment, impact of missing cognitive data, and survival bias, were carried out. Results: The most conservative estimate suggested that the age-specific prevalence of cognitive impairment declined by one fifth, from 11% in 2006/2007 to 9% in 2015. Decline was observed in all sensitivity analyses. The change was associated with differences in physical inactivity, management of high blood cholesterol, and increases in length education. Conclusion: Older adults in the Czech Republic, a country situated in the Central and Eastern European region, have achieved positive developments in cognitive aging. Longer education, better management of cardiovascular factors, and reduced physical inactivity seem to be of key importance.
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4. |
- Seblova, Dominika, et al.
(författare)
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Does Prolonged Education Causally Affect Dementia Risk When Adult Socioeconomic Status Is Not Altered? A Swedish Natural Experiment in 1.3 Million Individuals
- 2021
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Ingår i: American Journal of Epidemiology. - : Oxford University Press (OUP). - 0002-9262 .- 1476-6256. ; 190:5, s. 817-826
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Tidskriftsartikel (refereegranskat)abstract
- Intervening on modifiable risk factors to prevent dementia is of key importance, since progress-modifying treatments are not currently available. Education is inversely associated with dementia risk, but causality and mechanistic pathways remain unclear. We aimed to examine the causality of this relationship in Sweden using, as a natural experiment, data on a compulsory schooling reform that extended primary education by 1 year for 70% of the population between 1936 and 1949. The reform introduced substantial exogenous variation in education that was unrelated to pupils' characteristics. We followed 18 birth cohorts (n = 1,341,842) from 1985 to 2016 (up to ages 79-96 years) for a dementia diagnosis in the National Inpatient and Cause of Death registers and fitted Cox survival models with stratified baseline hazards at the school-district level, chronological age as the time scale, and cohort indicators. Analyses indicated very small or negligible causal effects of education on dementia risk (main hazard ratio = 1.01, 95% confidence interval: 0.98, 1.04). Multiple sensitivity checks considering only compliers, the pre-/post- design, differences in health-care-seeking behavior, and the impact of exposure misclassification left the results essentially unaltered. The reform had limited effects on further adult socioeconomic outcomes, such as income. Our findings suggest that without mediation through adult socioeconomic position, education cannot be uncritically considered a modifiable risk factor for dementia.
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5. |
- Seblova, Dominika, et al.
(författare)
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Thirty-year trends in dementia : a nationwide population study of Swedish inpatient records
- 2018
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Ingår i: Clinical Epidemiology. - 1179-1349. ; 10, s. 1679-1693
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Tidskriftsartikel (refereegranskat)abstract
- Background: The continuous growth of the current dementia epidemic is contingent on the stability of age- and sex-specific trends over time. However, recent evidence suggests declining or stable trends. The aim of this study was to evaluate the real-world changes in the burden of dementia in older adults in Sweden from 1987 to 2016 by estimating age- and sex-specific incidence of dementia diagnosis in hospital inpatient records (dementia incidence). Differences in trends by sex, age, and educational levels were also examined. Methods: The entire Swedish population aged 65 years and older was followed up from 1987 to 2016. Age-, sex-, and education-stratified dementia incidence rates for every follow-up year were estimated using the National Patient Register. Hazard ratio of receiving a dementia diagnosis in the inpatient records per 1 calendar year increase was estimated with discrete time logistic models with a complementary log-log link. Results: After increase, especially in those >85 years of age, dementia incidence started to decrease in the last 5 years of the study period. After 2011, 1 calendar year increase was associated with lower hazard ratio of receiving a hospital diagnosis of dementia. The decrease had the highest magnitude in 70-74-year-olds (5.5%), followed by 75-79-year-olds (-4.5%) and 80-84-year-olds (-4.0%). The decrease was present in both sexes and at all educational levels up to 90 years of age. Age was associated with the level of dementia incidence, and the trends differed by age group. Educational gradient was observed. University-educated older adults had the lowest rates of dementia. However, the trend over time did not substantially differ by sex or educational level. Conclusion: Our results provide more evidence that dementia incidence may be declining. They also suggest that at least in hospitals, the number of new patients with dementia may decrease in the future.
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6. |
- Svensson, Anna C., et al.
(författare)
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Residential area and physical activity : A multi-level study of 68,000 adults in Stockholm County
- 2017
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Ingår i: Scandinavian Journal of Public Health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 45:1, s. 25-32
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To determine whether there are systematic differences in physical activity between residential areas after extensive control for sociodemographic factors at the individual level. Methods: Multi-level regressions of walking/bicycling, sedentary activities, household work and exercise were carried out in a representative sample of 68,303 adults in 39 residential areas in Stockholm County, first adjusting at the individual level for country of birth, sex, age, education, occupational class and income. The type of housing was then considered at the individual level or, for walking/bicycling and exercise, at both the individual and area levels (as a measure of area density). Results: After adjustment for sociodemographic factors, differences between residential areas remained in walking/bicycling, corresponding to 0.27 SD, or 50 min/week between the most and least active areas. Forty per cent of this difference could be explained by the type of housing at the area level. For sedentary activities and household work, respectively, much of the variation that remained after adjustment for sociodemographic factors was, in turn, explained by the type of housing at the individual level, leaving a difference of 0.16 SD (80 min/week) and 0.13 SD (60 min/week), respectively. For exercise, the corresponding difference was 0.11 SD (11 min/week, not sensitive to housing). Conclusions: Area level factors may influence walking/bicycling. High area density was associated with more activity. However, high density also comes with a type of housing (apartments) that is associated with less household work and, surprisingly, more sedentary activities, introducing a challenging trade-off. The differences in exercise were smaller than for all other types of activities.
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