Neighbourhood effects and the real world beyond randomized community trials: a reply to Michael J Oakes.

We appreciate the positive opinion of Michael J Oakes 1 on our article 2 and his recognition of the contribution of our research group to the field of contextual epidemiology. We also understand that Oakes’ critics are not specifically directed at our publication but express a general concern on the use of observational approaches in research on neighbourhood and health. In the absence of randomization the possibilities for confounding are theoretically enormous. 3 Recognizing this may lead to a paralysing nihilism or to a radical ‘trialism’ (overemphasis of the advantages of randomized trials). 4,5