Complex interventions and study designs: Moving DOHaD forward
Director of the DSI-NRF Centre of Excellence in Human Development (both in South Africa) and principal investigator of the HeLTI SA project He is also president of DOHaD Africa and was co-convenor of this workshopThis workshop provided a forum for expert presentations and discussions of the importance and challenges of developing and implementing complex DOHaD interventions. The need for better evidence was a key theme that emerged through the day – so there is much more we all need to do to address the gaps!Dr Nigel Rollins from WHO highlighted (in a video presentation) that, before WHO can advocate preconception health guidelines to member states to invest in as a means of tackling child obesity, more robust data is needed. It was this realisation that gave birth to the Healthy Life Trajectories Initiative (HeLTI) several years ago https://www.who.int/
HeLTI is four harmonised RCTs in Canada, China, India and South Africa who are testing if a complex intervention implemented preconceptionally and through pregnancy, infancy, and childhood reduces child adiposity and metabolic risk, and improves development.
Professor Stephen Lye set the scene that preconception health may be an opportunity to optimise women’s health and have a triple benefit – good for her health now and for her future, and good for her offspring. Professor Shane Norris highlighted that when thinking of complex preconception interventions and study designs, it is important to review both recruitment and retention strategies – particularly considering the recruitment of fathers/partners to minimise the potential maternal factor overstatements and conclusions due to lack of including paternal contributing factors. It is also important to consider the enrolment of siblings as this may assist with non-measured household confounding factors. Retention strategies are important and include: (i) barrier reduction strategies, (ii) community building strategies, (iii) strategies to improve follow-up rates, and (iv) rracing strategies (see Teague S, et al. Retention strategies in longitudinal cohort studies. BMC Med Res Met. 2018; 18:151).
Professor Linda Richter articulated the time it takes to translate science into policy, and drew upon her journey working on Early Child Development that has resulted in global guidelines. Professor Lucilla Poston (President of the DOHaD Society) shared her insights around trials and challenged us to carefully think through design. Similarly, Professor Mary Barker challenged us to ensure process evaluation is incorporated into complex interventions to capture and understand context, implementation, and mechanisms of impact to better interpret trial results. Professor Caroline Fall shared a video documenting the Mumbai Maternal Nutrition Project, a preconception nutrition trial, which illustrated the discussion around the challenges of implementing complex interventions and the effort it takes to implement such studies. Professor Yajnik showcased the ethical challenges encountered during trials. Drs Huang, Matthew and Frazer concluded the workshop by sharing more detail around the HeLTI trials in terms of the: (i) Chinese cohort’s progress, challenges around recruitment and incentive strategies, (ii) harmonising biological sample collection and setting-up biorepositories to enable mechanistic studies into the trials, and (iii) the governance framework for HeLTI. A strength of the HeLTI platform is the purposeful intent to be harmonised and structures it has created to facilitate data and sample access.
Despite the challenges of complex interventions, these type of studies offer invaluable insights and opportunities. Watch this space!