So much of paediatrics, and medicine in general, is focused on small experimental or observational studies. This series of posts takes the wider view; we’re talking here about some of the biggest and longest running studies that help us frame, measure and understand childhood through time and across the world. This one is from Dunedin, Aotearoa
Who and what is being studied?
Described by international researchers as “… probably the world’s most successful longitudinal study of a general community sample, ever.”, the Dunedin Study has followed the lives of 1037 babies born in Dunedin, New Zealand between 1/04/1972 and 31/03/1973.
The original emphasis for the study was to focus on vulnerability around birth and shortly thereafter, and
“was partly motivated by the increased sophistication of birth technologies during the 1960s which had resulted in more babies surviving than ever before.” Poulton 2015
These vulnerabilities and life course events have enabled the researchers to understand some of the long-term effects of factors in childhood. The study has spawned a number of multigenerational studies involving the children of study members.
How good is the dataset?
Data was obtained at birth, 3, 5, 7, 9, 11, 15, 18 years of age throughout childhood, and subsequently at 21, 26, 32 and 38 years of age.
The study is widely known for not only its excellent, broad and relevant data, but also for the inordinately high retention rate of participants, most recently 95% of living participants at the 38 year-old review.
The study coordinators (and in my personal experience, participants) are intensely proud of this retention rate and have a strong sense of loyalty within the study.
Methods used to reduce barriers to forgoing participation includes simple measures like providing a creche on assessment days, to flying members back to Dunedin from around the world for review or sending interviewers to meet with incarcerated participants. Additionally, the assessments are designed to be engaging and to combat fatigue and boredom at each of the assessment points.
What meaning can be drawn from the results (so far)?
The study has generated over 1100 publications to date, notably:
That self-control in childhood is more important than socioeconomic status (SES) or IQ in predicting adults’ physical health, wealth, life satisfaction, addiction, crime, and parenting of the next generation. This study has been referenced in popular / mainstream media repeatedly.
Where next?
The Dunedin Study team are currently preparing for the 45 year assessments, which will include an fMRI study looking at the influence of early-life adversity on particular neural hubs and their core capacities.
How is this study funded?
The study was poorly funded initially, as it was not conceived as such a long-running sample. In the early years, there was a heavy reliance on community participation, including that of local doctor’s donating their time to assist with data collection, the free rental of church halls, and many volunteer hours. Subsequently, there was an increase in funding, not only from the NZ government (via their Health and Research council) and Otago University, but also significant international funding from the US National institute of health and the U.K. Medical research council.
Are there similar studies?
There are a number of similar studies either completed or in progress around the world, including the Ireland, Scotland, Netherlands, Germany, Victoria, Western Australia and Denmark, including . The Australian Institute of Family Studies lists more than 20 such studies, with some study populations into the tens of thousands! Check out the full list here.
For more on the Dunedin Study, check out their site at https://dunedinstudy.otago.ac.nz/
