Caesarean section and risk of type 1 diabetes: whole-of-population study.

AIM: A hypothesized mechanism for increased type 1 diabetes risk among caesarean births is lack of exposure to the vaginal microbiota. Children born by prelabour caesarean are not exposed to the vaginal microbiota, whereas caesarean births during labour (intrapartum) may be exposed. The aim of this study was to estimate type 1 diabetes risk among children born by caesarean compared with normal vaginal delivery. METHODS: This whole-of-population study linked routinely collected, de-identified administrative data from the South Australian Early Childhood Data Project for all births from 1999 to 2013. Type 1 diabetes cases were identified using inpatient hospitalizations from 2001 to 2014 (ICD-10-AM codes E10-E109). Type 1 diabetes risk for caesarean was assessed by Cox regression using two models: (i) caesarean vs. vaginal and (ii) prelabour or intrapartum caesarean vs. vaginal. Analyses were adjusted for confounding and multiple imputation was used to address missing data. RESULTS: A total of 286 058 children born between 1999 and 2013 contributed to 2 200 252 person-years, of which 557 had type 1 diabetes. Of all births, 90 546 (31.7%) were caesarean, and of these 53.1% were prelabour and 46.9% intrapartum caesarean. Compared with vaginal delivery, the adjusted hazard ratio for type 1 diabetes was 1.05 [95% confidence interval (CI) 0.86-1.28) for caesarean, 1.02 (95% CI 0.79-1.32) for prelabour caesarean and 1.08 (95% CI 0.82-1.41) for intrapartum caesarean. CONCLUSION: There may be a small increased type 1 diabetes risk following caesarean, but confidence intervals included the null. The lower estimate for prelabour compared with intrapartum caesarean, and the potential for unmeasured confounding suggest that neonatal vaginal microbiota might not be involved in type 1 diabetes.

Lessons learned from the AFLY5 RCT process evaluation: implications for the design of physical activity and nutrition interventions in schools.

BACKGROUND: Systematic reviews have highlighted that school-based diet and physical activity (PA) interventions have had limited effects. This study used qualitative methods to examine how the effectiveness of future primary (elementary) school diet and PA interventions could be improved. METHODS: Data are from the Active For Life Year 5 (AFLY5) study, which was a cluster randomised trial conducted in 60 UK primary schools. Year 5 (8-9 years of age) pupils in the 30 intervention schools received a 12-month intervention. At the end of the intervention period, interviews were conducted with: 28 Year 5 teachers (including 8 teachers from control schools); 10 Headteachers (6 control); 31 parents (15 control). Focus groups were conducted with 70 year 5 pupils (34 control). Topics included how the AFLY5 intervention could have been improved and how school-based diet and PA interventions should optimally be delivered. All interviews and focus groups were transcribed and thematically analysed across participant groups. RESULTS: Analysis yielded four themes. Child engagement: Data suggested that programme success is likely to be enhanced if children feel that they have a sense of autonomy over their own behaviour and if the activities are practical. School: Finding a project champion within the school would enhance intervention effectiveness. Embedding diet and physical activity content across the curriculum and encouraging teachers to role model good diet and physical activity behaviours were seen as important. Parents and community: Encouraging parents and community members into the school was deemed likely to enhance the connection between schools, families and communities, and "create a buzz" that was likely to enhance behaviour change. Government/Policy: Data suggested that there was a need to adequately resource health promotion activity in schools and to increase the infrastructure to facilitate diet and physical activity knowledge and practice. DISCUSSION AND CONCLUSIONS: Future primary school diet and PA programmes should find ways to increase child engagement in the programme content, identify programme champions, encourage teachers to work as role models, engage parents and embed diet and PA behaviour change across the curriculum. However, this will require adequate funding and cost-effectiveness will need to be established. TRIAL REGISTRATION: ISRCTN50133740.

A whole-of-population study of term and post-term gestational age at birth and children's development.

OBJECTIVE: To examine the risk of poor child development according to week of gestation at birth, among children born ≥ 37 weeks' gestation. DESIGN: Population-based study using linked data (n = 12,601). SETTING: South Australia. POPULATION: All births ≥ 37 weeks' gestation. METHODS: Relative risks of developmental vulnerability for each week of gestation were calculated with adjustment for confounders and addressing missing information. MAIN OUTCOME MEASURES: Child development was documented by teachers during a national census of children attending their first year of school in 2009, using the Australian Early Development Index (AEDI). Children scoring in the lowest 10% of the AEDI were categorised as developmentally vulnerable. RESULTS: The percentage of children vulnerable on one or more AEDI domains for the following gestational ages 37, 38, 39, 40, 41, 42-45 weeks was 24.8, 22.3, 20.6, 20.0, 20.4 and 24.2, respectively. Compared with children born at 40 weeks, the adjusted relative risks [(95% confidence interval (CI)] for vulnerability on ≥ 1 AEDI domain were; 37 weeks 1.13 (0.99-1.28), 38 weeks 1.05 (0.96-1.15), 39 weeks 1.02 (0.94-1.12), 41 weeks 1.00 (0.90-1.11) and 42-45 weeks 1.20 (0.84-1.72). CONCLUSIONS: Children born at 40-41 weeks' gestation may have the lowest risk of developmental vulnerability at school entry, reinforcing the importance of term birth in perinatal care. Early term or post-term gestational age at birth can help clinicians, teachers and parents recognise children with potential developmental vulnerabilities at school entry.

Are trajectories of self-regulation abilities from ages 2-3 to 6-7 associated with academic achievement in the early school years?

BACKGROUND: The aim of this study was to estimate the association between two key aspects of self-regulation, 'task attentiveness' and 'emotional regulation' assessed from ages 2-3 to 6-7 years, and academic achievement when children were aged 6-7 years. METHODS: Participants (n = 3410) were children in the Longitudinal Study of Australian Children. Parents rated children's task attentiveness and emotional regulation abilities when children were aged 2-3, 4-5 and 6-7. Academic achievement was assessed using the Academic Rating Scale completed by teachers. Linear regression models were used to estimate the association between developmental trajectories (i.e. rate of change per year) of task attentiveness and emotional regulation, and academic achievement at 6-7 years. RESULTS: Improvements in task attentiveness between 2-3 and 6-7 years, adjusted for baseline levels of task attentiveness, child and family confounders, and children's receptive vocabulary and non-verbal reasoning skills at age 6-7 were associated with greater teacher-rated literacy [B = 0.05, 95% confidence interval (CI) = 0.04-0.06] and maths achievement (B = 0.04, 95% CI = 0.03-0.06) at 6-7 years. Improvements in emotional regulation, adjusting for baseline levels and covariates, were also associated with better teacher-rated literacy (B = 0.02, 95% CI = 0.01-0.04) but not with maths achievement (B = 0.01, 95% CI = -0.01-0.02) at 6-7 years. For literacy, improvements in task attentiveness had a stronger association with achievement at 6-7 years than improvements in emotional regulation. CONCLUSIONS: Our study shows that improved trajectories of task attentiveness from ages 2-3 to 6-7 years are associated with improved literacy and maths achievement during the early school years. Trajectories of improving emotional regulation showed smaller effects on academic outcomes. Results suggest that interventions that improve task attentiveness when children are aged 2-3 to 6-7 years have the potential to improve literacy and maths achievement during the early school years.

Missing data on retrospective recall of early-life socio-economic position in surveillance systems: an additional disadvantage?

OBJECTIVES: Inclusion of information on early-life socio-economic position (SEP) in population chronic disease and risk factor surveillance systems enables better monitoring of effects of policies and interventions on health inequities and intergenerational disadvantage. Examining data quality, in terms of item non-response, informs choices about which indicators of early-life SEP to include in surveillance questionnaires. This study examined differences in recall of indicators of early-life SEP between different socio-economic groups. STUDY DESIGN: Cross-sectional population survey. METHODS: A representative population of people aged 18 years and over living in South Australia (n=2999) was selected at random from the electronic white pages, and a computer-assisted telephone interview was administered. RESULTS: Respondents with missing data on early-life SEP indicators were disadvantaged in terms of current SEP compared with those who provided this information. Among all respondents, the highest proportions of missing data were observed for maternal grandfather's main occupation (27.2%), and mother's (20.1%) and father's (19.6%) highest level of education. Family structure, housing tenure and family financial situation when the respondent was 10 years old, and mother's and father's main occupation were the indicators of early-life SEP that performed best in terms of recall. CONCLUSIONS: The differential response to early-life SEP questions according to current circumstances has implications for chronic disease surveillance examining the life-course impact of socio-economic disadvantage.

The increasing prevalence of diabetes in South Australia: the relationship with population ageing and obesity.

OBJECTIVES: To use representative population surveillance data to monitor and project changes in the prevalence of diabetes for different age and body mass index (BMI) groups. STUDY DESIGN: Representative, annual, face-to-face South Australian Health Omnibus Surveys, 1991-2003 (n=3000 per year). METHODS: Trends in self-reported diabetes prevalence by age group and BMI were examined. Separate projections were made on the basis of predicted changes in population demography and diabetes prevalence. RESULTS: The age-sex standardized absolute prevalence of self-reported diabetes among people aged 15 years and over increased from 3.5% in 1991 to 6.7% in 2003. If this current trend continues, the prevalence is expected to increase to 10.5% by 2016. The prevalence of diabetes was significantly higher among those classified as obese (6.5% in 1991 to 12.2% in 2003) than those with normal BMI. The greatest relative percentage increase in prevalence between 1991 and 2003 (169%) was seen among people aged 15-39 years. Taking both age group and BMI classification into account, the greatest relative percentage increases over this time were seen among those with normal BMI aged 60 years or older (148%), and those who were obese and aged less than 60 years (139%). CONCLUSIONS: The prevalence of diabetes and obesity increased significantly between 1991 and 2003. Population ageing and an increase in diabetes prevalence in the future will further increase the burden of diabetes. Future increases in diabetes prevalence are not inevitable, however, if investments are made in public health prevention programmes, particularly those addressing obesity.

A life-course approach to measuring socioeconomic position in population health surveillance systems.

Measuring socioeconomic position (SEP) in population chronic disease and risk factor surveillance systems is essential for monitoring socioeconomic inequalities in health over time. Life-course measures are an innovative way to supplement other SEP indicators in surveillance systems. A literature review examined the indicators of early-life SEP that could potentially be used in population health surveillance systems. The criteria of validity, relevance, reliability and deconstruction were used to determine the value of potential indicators. Early-life SEP indicators used in cross-sectional and longitudinal studies included education level, income, occupation, living conditions, family structure and residential mobility. Indicators of early-life SEP should be used in routine population health surveillance to monitor trends in the health and SEP of populations over time, and to analyse long-term effects of policies on the changing health of populations. However, these indicators need to be feasible to measure retrospectively, and relevant to the historical, geographical and sociocultural context in which the surveillance system is operating.

Underdiagnosed asthma in South Australia.

BACKGROUND: The prevalence of undiagnosed asthma in the general population and the clinical and demographic characteristics of these patients compared with those with diagnosed asthma are unclear. METHODS: The North West Adelaide Health Survey (NWAHS) is a population household interview survey of adults (age>18 years) in the north western suburbs of Adelaide, South Australia (regional population 0.6 million). Data obtained were weighted to the closest census data to provide population representative estimates. Positive answers to: "Have you ever had asthma?"; "Has it been confirmed by a doctor?"; "Do you still have asthma?" determined current physician diagnosed asthma. A positive bronchodilator response on spirometric testing according to ATS criteria without a physician's diagnosis determined undiagnosed asthma. Other measures included the SF-12 health survey questionnaire, the Selim index of severity of chronic lung disease, skin allergy tests, and demographic data. RESULTS: Of the 3422 individuals interviewed, 2523 (74%) agreed to participate in the clinical assessment. Of these, 292 (11.6%) had asthma, 236 (9.3%) with a doctor's diagnosis of asthma and 56 (2.3%) with undiagnosed asthma defined on spirometric criteria; thus, 19.2% of the total asthma group were undiagnosed. Those undiagnosed were more likely (p<0.05) to be >40 years old, on government benefits, with an income 65 years. Health service use over the previous year was similar for both asthma groups. CONCLUSION: Undiagnosed asthma is common among the Australian population, with a similar clinical spectrum to those with diagnosed asthma.

The Second Computer Assisted Telephone Interview (CATI) Forum: the state of play of CATI survey methods in Australia.

Computer Assisted Telephone Interview (CATI) systems are recognised in Australia and internationally for their ability to provide timely and relevant data on the health of the population. The Second CATI Population Health Surveys Forum highlighted the importance of this system for surveillance and using this information to determine priority health issues, develop strategies, monitor effectiveness of interventions, and influence health policy. A national CATI data collection strategy is required to determine priorities for health surveillance. Several development and technical issues need to be addressed for such a national strategy to provide a coordinated approach to health surveillance.

Multiple respiratory symptoms predict quality of life in chronic lung disease: a population-based study of Australian adults.

STUDY OBJECTIVES: Previous studies have shown that it is possible to improve the health-related quality of life (HRQoL) of chronic lung disease (CLD) patients without a concurrent change in morbidity. A valid CLD index that discriminates between different levels of CLD severity and is associated with HRQoL status is an important tool for primary care settings. In this study a symptom-based CLD index was assessed for its validity and relationship with HRQoL in a representative Australian population sample. The study also measured the prevalence of self-reported CLD. DESIGN: Representative population survey of adults aged 18 years and over using a multistage, systematic, clustered area sample. SETTING: Metropolitan Adelaide and country centres in South Australia with a population of over 1000 persons. PARTICIPANTS: Three hundred twenty-nine adults with CLD identified through a representative population survey of 3010 South Australians. MEASUREMENTS AND RESULTS: The CLD index and the SF-36 were administered to participants to assess the association between each subscale of the CLD index with each HRQoL scale. The CLD index was also used to assess the prevalence of CLD and the distribution of severity in self-reported CLD in the South Australian population. Each symptom sub-scale of the CLD index was significantly correlated with all scales of the SF-36. The prevalence of CLD as measured by the CLD index was 7.7% (mild), 2.2% (moderate) and 1.0% (severe). CONCLUSIONS: In the Australian context the CLD index is a reliable patient interview instrument that can be used to assess the effects of CLD on general HRQoL, improve assessment, and lead to interventions for physicians and their patients.