Question

In the cohort study by Wilding et al. (2020), children aged 4–5 years at baseline (10–11 years at follow-up) had height and weight measured at school at both time points. Environmental features included walkability, relative density of unhealthy food outlets, spaces for social interaction, natural greenspace coverage, supermarket density and measures of air pollution. It aimed to examine if such environmental characteristics at birth were related to the likelihood of overweight and obesity in childhood. Explain what the advantages and disadvantages of using a cohort study design like this are?

Answer 1

Here, individuals are being studied before the development of any form of obesity or overweight. This is the advantage of a cohort study. It allows the studies to be done in a temporal manner. As a result, the cause and effect relationship becomes clear. For instance, in the case mentioned, obesity or overweight will be present after being present in certain kind or kinds of environment. And hence, the study can give a causative relationship instead of just temporal.

Also, the controls are inherent in such studies. And thus, any biases due to pseudorandomization or choice of inappropriate controls can be ruled out.