Susan Morton

Life-Long Echoes – A Critical Analysis of the Developmental Origins of Adult Disease Model

The hypothesis that there is a developmental component to subsequent adult disease initially arose from epidemiological findings relating birth size to either indices of disease risk or actual disease prevalence in later life. While components of the epidemiological analyses have been challenged, there is strong evidence that developmental factors contribute to the later risk of metabolic disease – including insulin resistance, obesity, and heart disease – as well as have a broader impact on osteoporosis, depression and schizophrenia. We suggest that disease risk is greater when there is a mismatch between the early developmental environment (i.e., the phase of developmental plasticity) versus that experienced in mature life (i.e., adulthood), and that nutritional influences are particularly important. It is also critical to distinguish between those factors acting during the developmental phase that disrupt development from those influences that are less extreme and act through regulated processes of epigenetic change. A modelof the relationship between the developmental and mature environment is proposed and suggests interventional strategies that will vary in different population settings.

From Developmental Origins of Adult Disease to Life Course Research on Adult Disease and Aging: Insights from Birth Cohort Studies

Maturation of long-running birth cohort studies has fostered a life course approach to adult health, function, and disease and related to conceptual frameworks. Using broad concepts of human development including physical, cognitive, and emotional function, birth cohorts provide insights into the processes across the life course and between generations that link to adult outcomes. We discuss findings on the determinants and health consequences of lifetime trajectories of body size, cognitive and emotional function, and socioeconomic position. Findings from the studies suggest that, for some adult health outcomes, explanations will be incomplete unless exposures and processes from across the life course are taken into account. New birth cohort studies are poised to delineate further the nature and timing of life course relationships in contemporary generations of children.

Childhood Socioeconomic Position, Educational Attainment, and Adult Cardiovascular Risk Factors: The Aberdeen Children of the 1950s Cohort Study

OBJECTIVES We assessed the associations of childhood socioeconomic position with cardiovascular disease risk factors (smoking, binge alcohol drinking, and being overweight) and examined the roles of educational attainment and cognitive functioning in these associations. METHODS Data were derived from a cohort study involving 7184 individuals who were born in Aberdeen, Scotland, between 1950 and 1956; had detailed records on perinatal characteristics, childhood anthropometry, and cognitive functioning; and responded to a mailed questionnaire when they were aged 45 to 52 years. RESULTS Strong graded associations existed between social class at birth and smoking, binge drinking, and being overweight. Adjustment for educational attainment completely attenuated these associations. However, after control for adult social class, adult income and other potential confounding or mediating factors, some association remained. CONCLUSIONS Educational attainment is an important mediating factor in the relation between socioeconomic adversity in childhood and smoking, binge drinking, and being overweight in adulthood.

In the 21st Century, what is an acceptable response rate?

Response rates for epidemiologic studies have dropped dramatically over the past several decades, from rates of more than 90% in the 1950s to those that often struggle to reach 70%, and frequently are much lower. The obvious question for editors and reviewers of scientific papers is: “what is an acceptable response rate in the 21 Century?” This paper provides a discussion of this important and timely question. It suggests that there should be an expectation that response rates should be routinely, and accurately, reported in population-based studies, but argues that response rate alone may not be sufficient evidence to judge study quality and/or validity. It suggests that, in addition to reporting the response rates, requiring authors to disclose any known details about their non-participants, attempts to improve participation, and the denominators used to calculate response rates should assist editors and reviewers to assess the validity and utility of study findings more accurately and make decisions about their relevance for their readers.

Cohort Profile: Growing Up in New Zealand

Centre for Longitudinal Research – He Ara ki Mua, University of Auckland, Auckland, New Zealand, Growing Up in New Zealand, University of Auckland, Auckland, New Zealand, School of Medicine, University of Auckland, Auckland, New Zealand, Starship Children’s Hospital, Auckland District Health Board, Auckland, New Zealand, School of Population Health, University of Auckland, Auckland, New Zealand, Department of Public Health, School of Medicine and Health Sciences, University of Otago, Wellington, New Zealand, Office of the Deputy Vice-Chancellor (Māori), Massey University, Wellington, New Zealand, Bioinformatics Institute, University of Auckland, Auckland, New Zealand, Ministry of Pacific Island Affairs, Auckland Office, Auckland, New Zealand, Department of Psychology, University of Auckland, Auckland, New Zealand, Roy McKenzie Centre for the Study of Families, Victoria University, Wellington, New Zealand, Department of Psychology, University of Otago, Dunedin, New Zealand and School of Medical Sciences, University of Auckland, Auckland, New Zealand

Global summary of maternal and newborn vitamin D status – a systematic review

Pregnant women and newborns are at increased risk of vitamin D deficiency. Our objective was to create a global summary of maternal and newborn vitamin D status. We completed a systematic review (1959-2014) and meta-analysis of studies reporting serum 25-hydroxyvitamin D [25(OH)D] concentration in maternal and newborn populations. The 95 identified studies were unevenly distributed by World Health Organization (WHO) region: Americas (24), European (33), Eastern Mediterranean (13), South-East Asian (7), Western Pacific (16) and African (2). Average maternal 25(OH)D concentrations (nmol L(-1) ) by region were 47-65 (Americas), 15-72 (European), 13-60 (Eastern Mediterranean), 20-52 (South-East Asian), 42-72 (Western Pacific) and 92 (African). Average newborn 25(OH)D concentrations (nmol L(-1) ) were 35-77 (Americas), 20-50 (European), 5-50 (Eastern Mediterranean), 20-22 (South-East Asian), 32-67 (Western Pacific) and 27-35 (African). The prevalences of 25(OH)D <50 and <25 nmol L(-1) by WHO region in pregnant women were: Americas (64%, 9%), European (57%, 23%), Eastern Mediterranean (46%, 79%), South-East Asian (87%, not available) and Western Pacific (83%, 13%). Among newborns these values were: Americas (30%, 14%), European (73%, 39%), Eastern Mediterranean (60%, not available), South-East Asian (96%, 45%) and Western Pacific (54%, 14%). By global region, average 25(OH)D concentration varies threefold in pregnant women and newborns, and prevalence of 25(OH)D <25 nmol L(-1) varies eightfold in pregnant women and threefold in newborns. Maternal and newborn 25(OH)D concentrations are highly correlated. Addressing vitamin D deficiency in pregnant women and newborns should be a global priority. To protect children from the adverse effects of vitamin D deficiency requires appropriate interventions during both pregnancy and childhood.

Student engagement in very large classes: the teachers’ perspective

The rapid growth in the student population observed in higher education over the past 10–15 years in some countries has coincided with an increased recognition of student engagement and its value in developing knowledge. Active learning approaches have the potential to promote student engagement with lectures, but this becomes more challenging as class sizes increase. This study investigates student engagement from the teachers’ perspective, to identify current practices in teaching, learning and assessment designed to promote student engagement in courses with more than 1000 students enrolled at the University of Auckland, New Zealand. The study is based on semi‐structured interviews with six course coordinators. The results demonstrate that teaching techniques commonly associated with small‐class teaching can be used to engage students in very large classes. The effectiveness of these approaches from the students’ perspectives warrants further investigation.

'Growing up in New Zealand' cohort alignment with all New Zealand births

Objective: To compare the birth characteristics of the Growing Up in New Zealand cohort with those of all New Zealand (NZ) births over a similar time period, and to describe cohort alignment to current NZ births.

Early life factors, childhood cognition and postal questionnaire response rate in middle age: the Aberdeen Children of the 1950s study

BackgroundLittle is known about the relationship between early life factors and survey response in epidemiological studies of adults.MethodsThe Children of the 1950s cohort is composed of 12,150 children (boys 51.7%) born in Aberdeen 1950–56 and in primary schools in the city in 1962. Information on birth weight, gestational age, growth, behaviour and socio-economic position at birth and in childhood were obtained from contemporaneous records. Cognitive test scores at ages 7,9 and 11 years were also available from school records. The outcome was response to a postal questionnaire sent (2001–2003) to surviving cohort members in middle age.ResultsOf 11,282 potentially mailed subjects, 7,183 (63.7%) returned questionnaires. Response rates were highest among females, and those whose parents were married at birth, were in a non-manual social class at birth or in childhood, had fewer siblings, were taller and heavier in childhood for their age and had lower Rutter B behavioural scores. Childhood cognitive test scores at every age were strongly and positively related to the response rate to a postal questionnaire independently of other early life factors monotonically across the entire range of test scores. Those in the bottom fifth at age 11 had a response rate of 49% while those in the top fifth 75%.ConclusionThe strength and consistency of the association of childhood cognition with questionnaire response rate in middle age is surprisingly large. It suggests that childhood cognition across the entire normal range is a powerful influence on the complex set of later behaviours that comprise questionnaire response. The extent of possible response bias in epidemiological studies of the associations between childhood characteristics (particularly those related to cognition) and later health is probably larger than is generally realised, at least in situations where the survey instrument is a postal questionnaire.

How good is probabilistic record linkage to reconstruct reproductive histories? Results from the Aberdeen children of the 1950s study

BackgroundProbabilistic record linkage is widely used in epidemiology, but studies of its validity are rare. Our aim was to validate its use to identify births to a cohort of women, being drawn from a large cohort of people born in Scotland in the early 1950s.MethodsThe Children of the 1950s cohort includes 5868 females born in Aberdeen 1950–56 who were in primary schools in the city in 1962. In 2001 a postal questionnaire was sent to the cohort members resident in the UK requesting information on offspring. Probabilistic record linkage (based on surname, maiden name, initials, date of birth and postcode) was used to link the females in the cohort to birth records held by the Scottish Maternity Record System (SMR 2).ResultsWe attempted to mail a total of 5540 women; 3752 (68%) returned a completed questionnaire. Of these 86% reported having had at least one birth. Linkage to SMR 2 was attempted for 5634 women, one or more maternity records were found for 3743. There were 2604 women who reported at least one birth in the questionnaire and who were linked to one or more SMR 2 records. When judged against the questionnaire information, the linkage correctly identified 4930 births and missed 601 others. These mostly occurred outside of Scotland (147) or prior to full coverage by SMR 2 (454). There were 134 births incorrectly linked to SMR 2.ConclusionProbabilistic record linkage to routine maternity records applied to population-based cohort, using name, date of birth and place of residence, can have high specificity, and as such may be reliably used in epidemiological research.