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- Johannessen, Ane, et al.
(författare)
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Longterm follow-up in European respiratory health studies : patterns and implications
- 2014
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Ingår i: BMC Pulmonary Medicine. - : BioMed Central. - 1471-2466. ; 14, s. 63-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Selection bias is a systematic error in epidemiologic studies that may seriously distort true measures of associations between exposure and disease. Observational studies are highly susceptible to selection bias, and researchers should therefore always examine to what extent selection bias may be present in their material and what characterizes the bias in their material. In the present study we examined long-term participation and consequences of loss to follow-up in the studies Respiratory Health in Northern Europe (RHINE), Italian centers of European Community Respiratory Health Survey (I-ECRHS), and the Italian Study on Asthma in Young Adults (ISAYA). METHODS: Logistic regression identified predictors for follow-up participation. Baseline prevalence of 9 respiratory symptoms (asthma attack, asthma medication, combined variable with asthma attack and/or asthma medication, wheeze, rhinitis, wheeze with dyspnea, wheeze without cold, waking with chest tightness, waking with dyspnea) and 9 exposure-outcome associations (predictors sex, age and smoking; outcomes wheeze, asthma and rhinitis) were compared between all baseline participants and long-term participants. Bias was measured as ratios of relative frequencies and ratios of odds ratios (ROR). RESULTS: Follow-up response rates after 10 years were 75% in RHINE, 64% in I-ECRHS and 53% in ISAYA. After 20 years of follow-up, response was 53% in RHINE and 49% in I-ECRHS. Female sex predicted long-term participation (in RHINE OR (95%CI) 1.30(1.22, 1.38); in I-ECRHS 1.29 (1.11, 1.50); and in ISAYA 1.42 (1.25, 1.61)), as did increasing age. Baseline prevalence of respiratory symptoms were lower among long-term participants (relative deviations compared to total baseline population 0-15% (RHINE), 0-48% (I-ECRHS), 3-20% (ISAYA)), except rhinitis which had a slightly higher prevalence. Most exposure-outcome associations did not differ between long-term participants and all baseline participants, except lower OR for rhinitis among ISAYA long-term participating smokers (relative deviation 17% (smokers) and 44% (10-20 pack years)). CONCLUSIONS: We found comparable patterns of long-term participation and loss to follow-up in RHINE, I-ECRHS and ISAYA. Baseline prevalence estimates for long-term participants were slightly lower than for the total baseline population, while exposure-outcome associations were mainly unchanged by loss to follow-up.
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| 2. |
- Lonnebotn, Marianne, et al.
(författare)
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Late Breaking Abstract - Associations of fathers and their offsprings weight gain with non-allergic asthma
- 2018
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Ingår i: European Respiratory Journal. - : European Respiratory Society. - 0903-1936 .- 1399-3003. ; 52
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: We found that a father’s overweight in puberty was associated with non-allergic asthma in his future offspring.Aim: We explored the associations of both fathers and their offsprings own weight gain throughout the lifespan with offspring non-allergic asthma.Methods: We analysed questionnaire data from 3018 adult offspring (age 18-50) and their 2153 fathers (age 39-66) participating in the RHINESSA/RHINE generation study in 10 ECRHS centres in North Europe, Spain and Australia. The associations of fathers' and their offsprings weight gain was assessed by 9 body silhouettes (from lean to fat) self-reported for childhood, puberty and adult ages with non-allergic asthma in the offspring. It was analysed using a logistic regression model adjusted for parents and offspring variables, and cluster by family.Results: Non-allergic asthma was related to a weight gain of ≥2 body silhouettes from 8 years to puberty, both for fathers’ weight gain (OR 1.69; 95% CI 1.05-2.72; adjusted for fathers asthma, offspring body mass index, smoking and education) and for their offspring weight gain (1.77 [1.12-2.79], adjusted for parents´ education, smoking and asthma, and fathers´ weight gain from age 8 to puberty). If the father was overweight at puberty, in addition to having gained weight, non-allergic asthma in the offspring was more than tripled (3.53[1.80-6.94]; weight gain and adjustment as given above). No effect of weight gain from puberty or within adulthood in fathers’ or their offspring was observed.Conclusion: Non-allergic asthma was associated with weight gain from childhood to puberty. This was found both for personal weight gain and for having a father who gained weight.
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| 3. |
- Sengpiel, Verena, 1977, et al.
(författare)
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Folic acid supplementation, dietary folate intake during pregnancy and risk for spontaneous preterm delivery: a prospective observational cohort study
- 2014
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Ingår i: BMC Pregnancy and Childbirth. - : Springer Science and Business Media LLC. - 1471-2393. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Health authorities in numerous countries recommend periconceptional folic acid supplementation to prevent neural tube defects. The objective of this study was to examine the association of dietary folate intake and folic acid supplementation during different periods of pregnancy with the risk of spontaneous preterm delivery (PTD).MethodsThe Norwegian Mother and Child Cohort Study is a population-based prospective cohort study. A total of 66,014 women with singleton pregnancies resulting in live births in 2002¿2009 were included. Folic acid supplementation was self-reported from 26 weeks before pregnancy until pregnancy week 24. At gestational week 22, the women completed a food frequency questionnaire, which allowed the calculation of their average total folate intake from foods and supplements for the first 4¿5 months of pregnancy. Spontaneous PTD was defined as the spontaneous onset of delivery between weeks 22+0 and 36+6 (n = 1,755).ResultsThe median total folate intake was 313 ¿g/d (interquartile range IQR 167¿558) in the overall population and 530 ¿g/d (IQR 355¿636) in the supplement users. Eighty-five percent reported any folic acid supplementation from <8 weeks before to 24 weeks after conception while only 44% initiated folic acid supplementation before pregnancy. Cox regression analysis showed that the amount of dietary folate intake (hazard ratio HR 1.00; confidence interval 95% CI 0.61-1.65) and supplemental folate intake (HR 1.00; CI 1.00-1.00) was not significantly associated with the risk of PTD. The initiation of folic acid supplementation more than 8 weeks before conception was associated with an increased risk for spontaneous PTD (HR 1.18; CI 1.05-1.32) compared to no folic acid supplementation preconception. There was no significant association with PTD when supplementation was initiated within 8 weeks preconception (HR 0.99; CI 0.87-1.13). All analyses were adjusted for maternal characteristics and socioeconomic, health and dietary variables.ConclusionsOur findings do not support a protective effect of dietary folate intake or folic acid supplementation on spontaneous PTD. Preconceptional folic acid supplementation starting more than 8 weeks before conception was associated with an increased risk of spontaneous PTD. These results require further investigation before discussing an expansion of folic acid supplementation guidelines.
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