Comparative inequalities in child dental caries across four countries: Examination of international birth cohorts and implications for oral health policy.

Child dental caries (i.e., cavities) are a major preventable health problem in most high-income countries. The aim of this study was to compare the extent of inequalities in child dental caries across four high-income countries alongside their child oral health policies. Coordinated analyses of data were conducted across four prospective population-based birth cohorts (Australia, n = 4085, born 2004; Québec, Canada, n = 1253, born 1997; Rotterdam, the Netherlands, n = 6690, born 2002; Southeast Sweden, n = 7445, born 1997), which enabled a high degree of harmonization. Risk ratios (adjusted) and slope indexes of inequality were estimated to quantify social gradients in child dental caries according to maternal education and household income. Children in the least advantaged quintile for income were at greater risk of caries, compared to the most advantaged quintile: Australia: AdjRR = 1.18, 95%CI = 1.04-1.34; Québec: AdjRR = 1.69, 95%CI = 1.36-2.10; Rotterdam: AdjRR = 1.67, 95%CI = 1.36-2.04; Southeast Sweden: AdjRR = 1.37, 95%CI = 1.10-1.71). There was a higher risk of caries for children of mothers with the lowest level of education, compared to the highest: Australia: AdjRR = 1.18, 95%CI = 1.01-1.38; Southeast Sweden: AdjRR = 2.31, 95%CI = 1.81-2.96; Rotterdam: AdjRR = 1.98, 95%CI = 1.71-2.30; Québec: AdjRR = 1.16, 95%CI = 0.98-1.37. The extent of inequalities varied in line with jurisdictional policies for provision of child oral health services and preventive public health measures. Clear gradients of social inequalities in child dental caries are evident in high-income countries. Policy related mechanisms may contribute to the differences in the extent of these inequalities. Lesser gradients in settings with combinations of universal dental coverage and/or fluoridation suggest these provisions may ameliorate inequalities through additional benefits for socio-economically disadvantaged groups of children.

Household income and maternal education in early childhood and activity-limiting chronic health conditions in late childhood: findings from birth cohort studies from six countries.

BACKGROUND: We examined absolute and relative relationships between household income and maternal education during early childhood (<5 years) with activity-limiting chronic health conditions (ALCHC) during later childhood in six longitudinal, prospective cohorts from high-income countries (UK, Australia, Canada, Sweden, Netherlands, USA). METHODS: Relative inequality (risk ratios, RR) and absolute inequality (Slope Index of Inequality) were estimated for ALCHC during later childhood by maternal education categories and household income quintiles in early childhood. Estimates were adjusted for mother ethnicity, maternal age at birth, child sex and multiple births, and were pooled using meta-regression. RESULTS: Pooled estimates, with over 42 000 children, demonstrated social gradients in ALCHC for high maternal education versus low (RR 1.54, 95% CI 1.28 to 1.85) and middle education (RR 1.24, 95% CI 1.11 to 1.38); as well as for high household income versus lowest (RR 1.90, 95% CI 1.66 to 2.18) and middle quintiles (RR 1.34, 95% CI 1.17 to 1.54). Absolute inequality showed decreasing ALCHC in all cohorts from low to high education (range: -2.85% Sweden, -13.36% Canada) and income (range: -1.8% Sweden, -19.35% Netherlands). CONCLUSION: We found graded relative risk of ALCHC during later childhood by maternal education and household income during early childhood in all cohorts. Absolute differences in ALCHC were consistently observed between the highest and lowest maternal education and household income levels across cohort populations. Our results support a potential role for generous, universal financial and childcare policies for families during early childhood in reducing the prevalence of activity limiting chronic conditions in later childhood.

Breastfeeding and cortisol in hair in children.

BACKGROUND: One of the most important protective health factors for children is breast-feeding, but the mechanisms for this effect are not fully elucidated. Our objective was to assess if the duration of breastfeeding influences cortisol in hair, used as a biomarker for stress in children still at school-age. METHODS: ABIS (All Babies in Southeast Sweden) is a prospective population-based child cohort study of 17,055 children born Oct 1st1997- Oct 1st 1999, with the aim to study development of immune-mediated diseases. Questionnaires were answered at birth and then at regular follow-ups, and biological samples were collected. As a biomarker of stress, we measured the child's cortisol in hair collected at 8 years of age, those randomly selected N = 126 children among those with enough hair samples for analyses of hair at 8 years of age. Duration of breastfeeding had been registered as well as psycho-social factors related to breastfeeding and/or stress. RESULTS: There was a negative correlation (r = - 0.23, p = 0.01) between total duration of breastfeeding and hair cortisol levels at 8 years of age. In a multivariate analysis this association persisted (p = 0.01) even when adjusted for other potential intervening factors like age of mother at delivery and early psychosocial vulnerability in the family, an index based on 11 factors (Multivariate model: df = 5, adj R2 = 0.15, F = 5.38, p < 0.01). CONCLUSION: Our results show that longer breastfeeding is associated with lower cortisol levels in the child many years later. These associations should be more elaborated in further studies, and these findings also give some implications for public health. Mothers should be encouraged to breastfeed their children also in the modern society, since breastfeeding promotes health in the child. This information could be given via the obstetric departments and later at the well-baby clinics.

Using early childhood infections to predict late childhood antibiotic consumption: a prospective cohort study.

BACKGROUND: In the Swedish welfare system, the prescription and price of antibiotics is regulated. Even so, socioeconomic circumstances might affect the consumption of antibiotics for children. AIM: This study aimed to investigate if socioeconomic differences in antibiotic prescriptions could be found for children aged 2-14 years, and to find predictors of antibiotic consumption in children, especially if morbidity or socioeconomic status in childhood may function as predictors. DESIGN & SETTING: Participants were from All Babies In Southeast Sweden (ABIS), a prospectively followed birth cohort (N = 17 055), born 1997-1999. Pharmaceutical data for a 10-year period, from 2005-2014 were used (the cohort were aged from 5-7, up to 14-16 years). Participation at the 5-year follow-up was 7443 children. All prescriptions from inpatient, outpatient, and primary care were included. National registries and parent reports were used to define socioeconomic data for all participants. Most children's infections were treated in primary healthcare centres. METHOD: Parents of included children completed questionnaires about child morbidity at birth and at intervals up to 12 years. Their answers, combined with public records and national registries, were entered into the ABIS database and analysed. The primary outcome measure was the number of antibiotic prescriptions for each participant during a follow-up period between 2005-2014. RESULTS: The most important predictor for antibiotic prescription in later childhood was parent-reported number of antibiotic-treated infections at age 2-5 years (odds ratio (OR) range 1.21 to 2.23, depending on income quintile; P<0.001). In the multivariate analysis, lower income and lower paternal education level were also significantly related to higher antibiotic prescription. CONCLUSION: Parent-reported antibiotic-treated infection at age 2-5 years predicted antibiotic consumption in later childhood. Swedish doctors are supposed to treat all patients individually and to follow official guidelines regarding antibiotics, to avoid antibiotics resistance. As socioeconomic factors are found to play a role, awareness is important to get unbiased treatment of all children.

Inequalities in cardiovascular risks among Swedish adolescents (ABIS): a prospective cohort study.

OBJECTIVES: To investigate if socioeconomic status (SES) is predictive of cardiovascular risk factors among Swedish adolescents. Identify the most important SES variable for the development of each cardiovascular risk factor. Investigate at what age SES inequality in overweight and obesity occurs. DESIGN: Longitudinal follow-up of a prospective birth cohort. SETTING: All Babies in Southeast Sweden (ABIS) study includes data from children born between October 1997 and October 1999 in five counties of south east Sweden. PARTICIPANTS: A regional ABIS-study subsample from three major cities of the region n=298 adolescents aged 16-18 years, and prospective data from the whole ABIS cohort for overweight and obesity status at the ages 2, 5, 8 and 12 years (n=2998-7925). OUTCOME MEASURES: Blood pressure above the hypertension limit, overweight/obesity according to the International Obesity Task Force definition, low high-density lipoproteins (HDL) or borderline-high low-density lipoproteins according to National Cholesterol Education Program expert panel on cholesterol levels in children. RESULTS: For three out of four cardiovascular risk outcomes (elevated blood pressure, low HDL and overweight/obesity), there were increased risk in one or more of the low SES groups (p<0.05). The best predictor was parental occupational class (Swedish socioeconomic classification index) for elevated blood pressure (area under the receiver operating characteristic (ROC) curve 0.623), maternal educational level for overweight (area under the ROC curve 0.641) and blue-collar city of residence for low HDL (area under the ROC curve 0.641). SES-related differences in overweight/obesity were found at age 2, 5 and 12 and for obesity at age 2, 5, 8 and 12 years (all p<0.05). CONCLUSIONS: Even in a welfare state like Sweden, SES inequalities in cardiovascular risks are evident already in childhood and adolescence. Intervention programmes to reduce cardiovascular risk based on social inequality should start early in life.

[Public health differences between ¼the twin cities« persist]. / Folkhälsoskillnaderna består mellan Norrköping och Linköping - Kan inte förklaras av skillnader i hälso- och sjukvård utan snarare av olikheter i socioekonomi och livsstil.

A decade ago, major public health differences between two neighboring, equal sized large Swedish cities, Norrköping and Linköping (¼the Twin cities«) were revealed. These differences were considerable for cardiovascular mortality and life expectancy. An important finding was that cardiovascular mortality rates for men and women in the city of Norrköping were highest compared to other major Swedish cities. In this follow-up, a decade later, cardiovascular mortality rates are still highest for the Norrköping population in comparison to the largest Swedish cities. There are also still profound and major public health differences between these twin cities. The differences seem to persist over time. These differences could not be explained by differences in health care, but are rather reflecting different social history and socioeconomic and life style differences in these two cities.

Income inequality and social gradients in children's height: a comparison of cohort studies from five high-income countries.

BACKGROUND: Health and well-being are better, on average, in countries that are more equal, but less is known about how this benefit is distributed across society. Height is a widely used, objective indicator of child health and predictor of lifelong well-being. We compared the level and slope of social gradients in children's height in high-income countries with different levels of income inequality, in order to investigate whether children growing up in all socioeconomic circumstances are healthier in more equal countries. METHODS: We conducted a coordinated analysis of data from five cohort studies from countries selected to represent different levels of income inequality (the USA, UK, Australia, the Netherlands and Sweden). We used standardised methods to compare social gradients in children's height at age 4-6 years, by parent education status and household income. We used linear regression models and predicted height for children with the same age, sex and socioeconomic circumstances in each cohort. RESULTS: The total analytic sample was 37 063 children aged 4-6 years. Gradients by parent education and household income varied between cohorts and outcomes. After adjusting for differences in age and sex, children in more equal countries (Sweden, the Netherlands) were taller at all levels of parent education and household income than children in less equal countries (USA, UK and Australia), with the greatest between-country differences among children with less educated parents and lowest household incomes. CONCLUSIONS: The study provides preliminary evidence that children across society do better in more equal countries, with greatest benefit among children from the most disadvantaged socioeconomic groups.

Introduction of complementary foods in Sweden and impact of maternal education on feeding practices.

OBJECTIVE: To describe the introduction of complementary foods in a population-based cohort in relation to recommendations and explore the possible impact of maternal education on infant feeding practices. DESIGN: Prospective data from the All Babies in Southeast Sweden (ABIS) cohort study were used. The ABIS study invited all infants born in south-east Sweden during October 1997-October 1999 (n 21 700) to participate. A questionnaire was completed for 16 022 infants. During the infants' first year parents continuously filed in a diary covering introduction of foods. SETTING: Sweden. SUBJECTS: Infants (n 9727) with completed food diaries. RESULTS: Potatoes, vegetables, fruits/berries and porridge were the foods first introduced, with a median introduction between 19 and 22 weeks, followed by introduction of meat, cow's milk, follow-on formula and sour milk/yoghurt between 24 and 27 weeks. Early introduction of any food, before 16 weeks, occurred for 27 % of the infants and was more common in infants of mothers with low education. Overall, potatoes (14·7 %), vegetables (11·1 %), fruits/berries (8·5 %), porridge (7·4 %) and follow-on formula (2·7 %) were the foods most frequently introduced early. The majority of infants (≥70 %) were introduced to potatoes, vegetables, fruits/berries and porridge during concurrent breast-feeding, but introduction during concurrent breast-feeding was less common in infants of mothers with low education. CONCLUSIONS: Most infants were introduced to complementary foods timely in relation to recommendations. Low maternal education was associated with earlier introduction of complementary foods and less introduction during concurrent breast-feeding. Still, the results indicated exposure to fewer foods at 12 months in infants of mothers with low education.

Maternal influence on child HPA axis: a prospective study of cortisol levels in hair.

OBJECTIVE: To investigate cortisol concentrations in hair as biomarker of prolonged stress in young children and their mothers and the relation to perinatal and sociodemographic factors. METHODS: Prospective cohort study of 100 All Babies In Southeast Sweden study participants with repeated measures at 1, 3, 5, and 8 years and their mothers during pregnancy. Prolonged stress levels were assessed through cortisol in hair. A questionnaire covered perinatal and sociodemographic factors during the child's first year of life. RESULTS: Maternal hair cortisol during the second and third trimester and child hair cortisol at year 1 and 3 correlated. Child cortisol in hair levels decreased over time and correlated to each succeeding age, between years 1 and 3 (r = 0.30, P = .002), 3 and 5 (r = 0.39, P < .001), and 5 and 8 (r = 0.44, P < .001). Repeated measures gave a significant linear association over time (P < .001). There was an association between high levels of hair cortisol and birth weight (ß = .224, P = .020), nonappropriate size for gestational age (ß = .231, P = .017), and living in an apartment compared with a house (ß = .200, P = .049). In addition, we found high levels of cortisol in hair related to other factors associated with psychosocial stress exposure. CONCLUSIONS: Correlation between hair cortisol levels in mothers and their children suggests a heritable trait or maternal calibration of the child's hypothalamic-pituitary-adrenocortical axis. Cortisol output gradually stabilizes and seems to have a stable trait. Cortisol concentration in hair has the potential to become a biomarker of prolonged stress, especially applicable as a noninvasive method when studying how stress influences children's health.

Higher maternal education is associated with favourable growth of young children in different countries.

BACKGROUND: Childhood growth affects long-term health and could contribute to health inequalities that persist throughout life. METHODS: We compared growth data of 4-year-old to 6-year-old children born 1997-2002 in UK (n=15,168), Sweden (n=6749) and rural China (n=10,327). SD scores (SDS) were calculated against the WHO Growth Standard. Obesity and overweight were defined by the International Obesity Taskforce cut-offs, and stunting, underweight and thinness by height, weight or body mass index (BMI)<-2 SDS. Associations with maternal education were standardised by calculating the Slope Index of Inequality (SII). RESULTS: Mean SDS height, weight and BMI in the UK (-0.01, 0.42, 0.62, respectively) and Sweden (0.45, 0.59, 0.45) were higher than in China (-0.98, -0.82, -0.29). Higher maternal education was consistently associated with taller offspring height SDS (SII: UK 0.25; Sweden 0.17; China 1.06). Underweight and stunting were less common in the UK (prevalence: 0.6% and 2.2%, respectively) and Sweden (0.3% and 0.6%) than in China (9.5% and 16.4%), where these outcomes were inversely associated with maternal education (SII: -25.8% and -12.7%). Obesity prevalence in the UK, Sweden and China was 4.8%, 3.7% and 0.4%, respectively. Maternal education was inversely associated with offspring obesity in the UK (SII: -3.3%) and Sweden (-2.8%), but not in China (+0.3%). CONCLUSIONS: Higher maternal education was associated with more favourable growth in young children: lower obesity and overweight in the UK and Sweden, and lower stunting and underweight in rural China. Public health strategies to optimise growth in early childhood need to acknowledge socioeconomic factors, but possibly with a different emphasis in different settings.

"My parents decide if I can. I decide if I want to." Children's views on participation in medical research.

The participation of children in medical research raises many ethical issues, in particular regarding assent. However, little is known about children's own views on participation. This study presents results from interviews with children 10-12 years old with and without experience in a large-scale longitudinal screening study. We identified five themes: (1) knowledge about research, (2) a sense of altruism, (3) shared decision-making and right to dissent, (4) notions of integrity, privacy, and access, and (5) understanding of disease risk and personal responsibilities. We conclude that the children feel positive towards medical research, and want to take an active part in decisions and have their integrity respected. However, the study also indicates that children who had participated in longitudinal screening had a limited understanding, suggesting the vital importance of providing information appropriate to their age and maturity. This information should be provided out of respect for the children as persons, but also to promote their willingness to continue participating in longitudinal studies.

Breastfeeding patterns of mothers with type 1 diabetes: results from an infant feeding trial.

BACKGROUND: Both the initiation and maintenance of breastfeeding have been reported to be negatively affected by maternal type 1 diabetes (T1D). The aim of this study was to prospectively examine the breastfeeding patterns among mothers with and without T1D participating in a large international randomized infant feeding trial (TRIGR). METHODS: Families with a member affected by T1D and with a newborn infant were invited into the study. Those who had HLA-conferred genetic susceptibility for T1D tested at birth with gestation > 35 weeks and were healthy were eligible to continue in the trial. Among the 2160 participating children, 1096 were born to women with T1D and 1064 to unaffected women. Information on infant feeding was acquired from the family by frequent prospective dietary interviews. RESULTS: Most (>90%) of the infants of mothers with and without T1D were initially breastfed. Breastfeeding rates declined more steeply among mothers with than without T1D being 50 and 72% at 6 months, respectively. Mothers with T1D were younger, less educated and delivered earlier and more often by caesarean section than other mothers (p < 0.01). After adjusting for all these factors associated with the termination of breastfeeding, there was no difference in the duration of breastfeeding among mothers with and without T1D. CONCLUSIONS: Maternal diabetes status per se was not associated with shorter breastfeeding. The lower duration of breastfeeding in mothers with T1D is largely explained by their more frequent caesarean sections, earlier delivery and lower age and education.

Cryopreserved peripheral blood mononuclear cells are suitable for the assessment of immunological markers in type 1 diabetic children.

Cryopreserved peripheral blood mononuclear cells (PBMC) are commonly used when assessing immune responses in clinical trials, both for practical reasons and to minimize interassay variation, as samples are often collected and studied over time. This study investigated the effect of cryopreservation on cytokine and chemokine secretion, and on expression of regulatory T-cell associated markers, in samples from children with type 1 diabetes. PBMC were cultured before and after cryopreservation either with GAD(65) or PHA. Secretion of cytokines (IL-5, -6, -10, -12, -13 -17, IFN-gamma and TNF-alpha) and chemokines (IP-10, MCP-1, MIP-1alpha, MIP-1beta and RANTES) was analysed in cell supernatants using multiplex fluorochrome technique (Luminex). Expression of FOXP3 and TGF-beta mRNA was detected by multiplex real-time RT-PCR. Increased spontaneous secretion of IL-6, -10, -12, -13, IFN-gamma and MCP-1, and mRNA expression of FOXP3 and TGF-beta, was detected after cryopreservation. Stimulation with GAD(65) induced higher levels of IL-6, IFN-gamma, TNF-alpha and MIP-1alpha, whereas lower secretion was found for IL-10 and IL-13 in cryopreserved PBMC. Stimulation with PHA induced lower secretion of IP-10, MCP-1 and RANTES and FOXP3 mRNA expression after cryopreservation. Thus, cryopreserved PBMC were suitable to assess the immunological markers included in this study, even though their expression could differ from freshly handled cells.

Mixed-meal tolerance test versus glucagon stimulation test for the assessment of beta-cell function in therapeutic trials in type 1 diabetes.

OBJECTIVE: Beta-cell function in type 1 diabetes clinical trials is commonly measured by C-peptide response to a secretagogue in either a mixed-meal tolerance test (MMTT) or a glucagon stimulation test (GST). The Type 1 Diabetes TrialNet Research Group and the European C-peptide Trial (ECPT) Study Group conducted parallel randomized studies to compare the sensitivity, reproducibility, and tolerability of these procedures. RESEARCH DESIGN AND METHODS: In randomized sequences, 148 TrialNet subjects completed 549 tests with up to 2 MMTT and 2 GST tests on separate days, and 118 ECPT subjects completed 348 tests (up to 3 each) with either two MMTTs or two GSTs. RESULTS: Among individuals with up to 4 years' duration of type 1 diabetes, >85% had measurable stimulated C-peptide values. The MMTT stimulus produced significantly higher concentrations of C-peptide than the GST. Whereas both tests were highly reproducible, the MMTT was significantly more so (R(2) = 0.96 for peak C-peptide response). Overall, the majority of subjects preferred the MMTT, and there were few adverse events. Some older subjects preferred the shorter duration of the GST. Nausea was reported in the majority of GST studies, particularly in the young age-group. CONCLUSIONS: The MMTT is preferred for the assessment of beta-cell function in therapeutic trials in type 1 diabetes.

Socio-economic determinants, maternal smoking and coffee consumption, and exclusive breastfeeding in 10205 children.

AIM: To examine socio-economic factors, smoking, coffee consumption and exclusive breastfeeding duration. METHODS: This study was part of a prospective cohort study of children born between 1 October 1997 and 1 October 1999 (the All Babies in Southeast Sweden (ABIS) study). Eleven socio-economic characteristics (parental employment, civil status, whether parents were born in Sweden, parental education, residence at birth and during child's first year, crowded living), maternal smoking, coffee consumption, infant sex, siblings, parental age, and maternal alcohol consumption during pregnancy were analysed using logistic regression and Cox's proportional hazards method. All data were obtained through questionnaires distributed at infant birth and at 1 y of age. Exclusive breastfeeding duration<4 mo and actual breastfeeding duration were our main outcome measures. RESULTS: Out of 10205 infants, 2206 (21.6%) were exclusively breastfed for less than 4 mo ("short exclusive breastfeeding"; SEBF). Backward stepwise regression analysis identified the following risk factors for SEBF: maternal smoking (95% confidence interval for adjusted odds ratio, 95% CI AOR 2.00-2.82), low maternal education (95% CI AOR 1.45-2.19), maternal employment less than 3 mo during pregnancy (95% CI AOR 1.17-1.54), paternal age

Assessment of smoking behaviors in the home and their influence on children's passive smoking: development of a questionnaire.

PURPOSE: To construct and validate a questionnaire aiming to measure children's exposure to environmental tobacco smoke (ETS) in the home. METHODS: The development of the instrument included epidemiological studies, qualitative interviews, pilot studies, and validation with biomarkers and is described in seven consecutive steps. Parents of preschool children, from different population-based samples in south-east Sweden, have participated in the studies. RESULTS: Content and face validity was tested by an expert panel and core elements for the purpose of the instrument identified. Reliability was shown with test-retest of the first version. The validation with biomarkers indicated that the sensitivity of the instrument was high enough to discriminate between children's ETS exposure levels. Cotinine/creatinine levels were related to parents' described smoking behaviors. Differences were shown between children from non-smoking homes, and all groups with smoking parents, independent of their smoking behavior (p < 0.01), as well as between parents smoking strictly outdoors and parents reporting indoor smoking (p < 0.001). CONCLUSION: The results indicate that the presented instrument can be used to discriminate between different levels of ETS exposure and when children's level of tobacco smoke exposure is to be assessed.

Parents' attitudes to children's tobacco smoke exposure and how the issue is handled in health care.

INTRODUCTION: The objective of the study was to understand the opinions and attitudes among parents of preschool children towards children's passive smoking, to show how attitudes influenced smoking and smoking behavior, and how the parents had experienced the handling of the tobacco issue in antenatal and child health care. METHOD: A subsample of smoking and nonsmoking parents (n = 300) with 4- to 6-year-old children participating in All Babies in Southeast Sweden (ABIS), a prospective study on environmental factors affecting development of immune-mediated diseases, answered a questionnaire on their opinions and attitudes to children's passive smoking. RESULTS: Indoor smokers were more positive regarding smoking, less aware of the adverse health effects from passive smoking, and more negative regarding the handling of tobacco prevention in health care than both outdoor smokers and nonsmokers. Indoor smokers' idea of how children should be protected from tobacco smoke exposure was significantly different from the idea of nonsmokers and outdoor smokers. DISCUSSION: Results indicate that further intense efforts are needed to convince the remaining indoor smokers about the adverse health effects related to tobacco smoke exposure. Pediatric nurses meet these parents in their daily work and should be aware of the need to focus this group and their use of protective measures.