| 1. |
- Björk, Jonas, et al.
(författare)
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An efficient sampling strategy for selection of biobank samples using risk scores
- 2017
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Ingår i: Scandinavian Journal of Public Health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 45:17_suppl, s. 41-44
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The aim of this study was to suggest a new sample-selection strategy based on risk scores in case-control studies with biobank data. Methods: An ongoing Swedish case-control study on fetal exposure to endocrine disruptors and overweight in early childhood was used as the empirical example. Cases were defined as children with a body mass index (BMI) ≥18 kg/m2 (n=545) at four years of age, and controls as children with a BMI of 1/217 kg/m2 (n=4472 available). The risk of being overweight was modelled using logistic regression based on available covariates from the health examination and prior to selecting samples from the biobank. A risk score was estimated for each child and categorised as low (0-5%), medium (6-13%) or high (≥14%) risk of being overweight. Results: The final risk-score model, with smoking during pregnancy (p=0.001), birth weight (p<0.001), BMI of both parents (p<0.001 for both), type of residence (p=0.04) and economic situation (p=0.12), yielded an area under the receiver operating characteristic curve of 67% (n=3945 with complete data). The case group (n=416) had the following risk-score profile: low (12%), medium (46%) and high risk (43%). Twice as many controls were selected from each risk group, with further matching on sex. Computer simulations showed that the proposed selection strategy with stratification on risk scores yielded consistent improvements in statistical precision. Conclusions: Using risk scores based on available survey or register data as a basis for sample selection may improve possibilities to study heterogeneity of exposure effects in biobank-based studies.
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| 2. |
- Malmqvist, Ebba, et al.
(författare)
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Maternal Exposure to Air Pollution and Birth Outcomes.
- 2011
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Ingår i: Environmental Health Perspectives. - : Environmental Health Perspectives. - 1552-9924 .- 0091-6765. ; 119, s. 553-558
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Tidskriftsartikel (refereegranskat)abstract
- Background: The knowledge about air pollution effects on birth weight, prematurity and small for gestational age [SGA] in low-exposure areas is insufficient. Objectives: The aim of this birth cohort study was to investigate if low-level exposure to air pollution was associated with prematurity and foetal growth and if there are gender specific effects. Method: We combined high quality registry information on 81110 births with individually modeled exposure data at residence for nitrogen oxides [NOx] and proximity to roads with differing traffic density. The data were analyzed by using logistic and linear regression with and without potential confounders. Results: An increased risk for babies being SGA was observed when highest and lowest NOx quartiles were compared, adjusting for maternal age, smoking, gender and year of birth. After additional adjustment for maternal country of origin and parity (which were highly intercorrelated), the increase was no longer statistically significant. However, in subgroup analysis when highest and lowest NOx quartiles were compared, there was still an increased risk for SGA for baby girls Odds Ratio [OR] 1.12 (95% Confidence Interval [CI] 1.01, 1.24), and also if mothers had not changed residency during pregnancy OR 1.09 (95% CI 1.01, 1.18). The confounders with the greatest impact on SGA were parity and country of origin. Concerning prematurity, the prevalence was lower in the three higher NOx exposure quartiles compared to the lowest category. Conclusion: For future studies on air pollution effects on birth outcomes careful control of confounding is crucial.
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| 3. |
- Martinsson, Matilda, et al.
(författare)
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Intrauterine exposure to perfluorinated compounds and overweight at age 4 : A case-control study
- 2020
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 15:3
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Tidskriftsartikel (refereegranskat)abstract
- Aims The aims were to investigate the association between maternal serum levels of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS) and perfluorononanoic acid (PFNA) in early pregnancy and overweight in the child at 4 years and to assess potential heterogeneity in exposure effect between strata with different levels of other risk factors for overweight. Methods We used a case-control design and included 354 cases (ISO-BMI ≥ 18 kg/m2) and 2 controls per case (ISO-BMI ≤17 kg/m2) from child health care centers in Malmö, Sweden. Controls were selected stratified on risk scores for overweight in a propensity score framework. Maternal serum levels were analyzed in biobanked samples collected by routine around gestational week 14. Logistic regression was used to estimate odds ratios between quartiles of maternal serum levels and child overweight at age 4. Results There were no consistent monotonic exposure-response relationships. We found some significant odds ratios in specific quartiles but these were regarded as spurious findings. The absence of an effect was consistent over risk strata. Conclusions We did not find evidence of an association between maternal serum levels of PFOS, PFOA, PFHxS and PFNA in early pregnancy and child overweight at age 4. The level of other risk factors for overweight did not affect children’s susceptibility to prenatal PFAS exposure.
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| 4. |
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| 5. |
- Weimann, Hanna, et al.
(författare)
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Effects of changing exposure to neighbourhood greenness on general and mental health: A longitudinal study.
- 2015
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Ingår i: Health and Place. - : Elsevier BV. - 1873-2054 .- 1353-8292. ; 33, s. 48-56
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Tidskriftsartikel (refereegranskat)abstract
- Green neighbourhood environments have been associated with physical and psychological wellbeing in adults. Access to greenness is potentially more important in vulnerable subgroups. In this study based on longitudinal survey data from southern Sweden the cohort was divided into prognostic groups for good self-reported general (n=8891) and mental (n=9444) health. We used independent survey data to assess perceived neighbourhood greenness in 1km(2) areas, and estimated effects of changing exposure longitudinally stratified by prognostic group. The overall effect on health was small and statistically uncertain (for general health OR 1.04, 95% CI 0.98-1.10, for mental health OR 1.07, 95% CI 1.00-1.14). A more beneficial effect of increased greenness was indicated among subjects with lowest prognostic of good general health (OR 1.24, 95% CI 1.01-1.52). The study provided only weak evidence for beneficial effects of increased neighbourhood greenness triggered by changing residence. It seems that altered life circumstances, e.g. changed civil or socioeconomic status that often trigger a decision to move, are also the key determinants of the health consequences of changing residence.
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| 6. |
- Weimann, Hanna, et al.
(författare)
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Neighborhood environment and physical activity among young children: A cross-sectional study from Sweden
- 2015
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Ingår i: Scandinavian Journal of Public Health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 43:3, s. 283-293
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Tidskriftsartikel (refereegranskat)abstract
- Aims: The aims of this study were to investigate the association between the neighbourhood environment and physical activity among young children in a Scandinavian setting, and to assess the influences of seasonal variations, age, sex and parental education. Methods: Physical activity was assessed with an accelerometer and neighbourhood resources were estimated using geographic information systems for 205 Swedish children aged 4-11 years. Neighbourhood resources were generated as the sum of three neighbourhood attributes: (a) foot and bike paths, (b) non-restricted destinations and (c) recreational area, all within 300 m of each child's home. Physical activity was assessed as: (a) total volume of physical activity (i.e. counts per minute), (b) sedentary time and (c) moderate to vigorous physical activity (MVPA). The association between neighbourhood resources and physical activity was analysed using mixed linear models weighted by measurement time and adjusted for sex, age, season of activity measurement, type of housing and parental education. Results: Children were more physically active in areas with intermediate access to neighbourhood resources for physical activity compared to areas with worst access, while the difference between intermediate and best neighbourhood resource areas was less clear. The association between physical activity and neighbourhood resources was weaker than with seasonal variations but compatible in magnitude with sex, age, type of housing and parental education. Among specific neighbourhood attributes, the amount of foot and bike paths was associated with less sedentary time and more MVPA. Conclusions:This study provides some, not entirely consistent, evidence overall for an association between the neighbourhood environment and physical activity among young children in Scandinavia. © 2015 the Nordic Societies of Public Health.
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| 7. |
- Weimann, Hanna, et al.
(författare)
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Perception of safety is a prerequisite for the association between neighbourhood green qualities and physical activity : Results from a cross-sectional study in Sweden
- 2017
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Ingår i: Health and Place. - : Elsevier BV. - 1353-8292 .- 1873-2054. ; 45, s. 124-130
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we assess how the Scania Green Score (SGS5), and the five distinct perceived neighbourhood green dimensions within this area-aggregated index (1 km2 squares), is associated with self-reported physical activity and general health, and if perceived safety and social coherence has a moderating effect. Two independent surveys, both conducted in Scania, Sweden, was used for data on SGS5 and health outcomes (N=28 198 and N=23 693), respectively. SGS5 was more clearly associated with physical activity (OR 1.06; 95% CI 1.02–1.10) than with general health (OR 1.02; 95% CI 1.00–1.04). This association was moderated by safety (p for interaction <0.001); SGS5 was positively associated with physical activity only among individuals who perceived high safety in their neighbourhood (OR 1.07; 95% CI 1.02–1.11). No moderating effect was seen for social coherence. Among specific dimensions, cultural history was positively associated with both physical activity and general health. Our results suggest that perception of safety is a prerequisite for the positive effects of neighbourhood green qualities.
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