Shortcuts to randomised evidence: Using existing trials in early life for follow-up studies

摘要

There is a paucity of evidence from randomised trials in humans supporting the DOHaD hypothesis, although recent nutrient supplementation trials in pregnancy have shown promise with respect to the primary prevention of childhood asthma. However, setting up de novo trials is expensive and time-consuming. A cheaper, more efficient, and underused approach is to follow-up children from existing trial cohorts to collect new outcomes of interest, other than those originally intended. For example, the majority of prenatal interventions have focused on pregnancy/perinatal outcomes, and have not followed up the offspring into childhood, even though the prenatal exposure of interest may have biological relevance to the developmental programming of health and disease later in life. Given that modification of the early life exposure has been randomised, this approach has the potential to provide more robust evidence for causal inference than can be obtained from observational studies which may often be confounded, and can give added value to the original trial. Seif Shaheen will illustrate this 'short cut' approach to obtaining randomised evidence with examples of prenatal nutrient supplementation trials which were undertaken with particular outcomes in mind, but which have provided opportunities to measure new childhood outcomes, especially in relation to respiratory health.