Participants head back to birth city
Hundreds of participants, including some from across the world, are set to return to the New Zealand city where they were born a half century ago.
They were part of the world-leading Dunedin Study, a longitudinal study of 1037 babies born in that city’s Queen Mary Maternity Hospital between April 1, 1972, and March 31, 1973.
Those unnamed individuals have become part of the the most detailed study of human health and development in the world, with 94% of living members taking part in the age 45 assessments. Regularly studied since they were born, their last assessment was when they were 45, but from April 8 researchers start the age 52 assessment.
Those assessments, which take two years to compete, would take a full day and involved an array of physical checks, including a dental examination, vision, hearing and respiratory tests, and will answer many questions about their lives. They will also attend a brain MRI scan on a second day.
The secret to the study’s success was the high retention rate of those participants, study director research Professor Moana Theodore said. “That’s important because it means we get to see people from all walks of life.”
While all those in the study were born in Dunedin, a quarter now live overseas – primarily in Australia, while 15% are in the North Island and the remainder in the South Island.
“The study members have been incredibly committed to the study – a half-century commitment from them and their families.”
A longitudinal study would not be reporting about what life was like at 52 for a participant, but more about using previous data “to find things from when they were younger that now influenced their health now”.
Theodore said the previous assessment phase took place between 2017 to 2019, and “we were very fortunate, unlike some other studies, to not be affected during our data collection part of the study by Covid”.
But the impact of Covid on the lives of participants, including long Covid, would form part of the latest assessment.
She was particularly interested in how people were ageing given the equities and inequities they may have faced growing-up.
Research from the longitudinal study led to more than 1400 peer-reviewed journal articles, books and reports on many aspects of human health and development being published. That made an impact on pubic policy from everything from the high rates of glue ear to injury-prevention information such as the fitting of thermostats into the water cylinders, and the shortening of cords for electric kettles.
Recent findings have included self-regulation, with children who showed higher amounts of perseverance or delaying gratification, would go on to have better health outcomes in adulthood.
A key interest for those researching the participants at 52 was ageing, which was tested by certain biological markers. A previous study of when participants were chronologically all aged 38, showed their biological ages ranged between early 20s nearly 60 years of age.
The question of ageing, particularly over the next couple of assessment phases, would be important for not only researchers but also policy makers when addressing issues such as pension eligibility.
“Mid-life is an understudied period of time when it comes to understanding health and wellbeing.”
Asked about key lesson from the Dunedin Study, Theodore said it showed it was normal to have had at least one mental health condition during a life, and it was “not normal” for people not to suffer from a mental health issue at some stage by the time they reached middle age. “That helps reduce the stigma.”
Theodore is the third study director in the 51 years, and the first director who is Generation X – the same generation as the study members. She was named director in October last year, after the death of former director Emeritus Distinguished Professor Richie Poulton.
“Richie was a long-time mentor of mine,” she said. “He knew that the data that we collect would become more and more valuable and helpful over time – that the best years of the study were still to come.”