Most randomised trials allocate individual participants to different treatments. However,
cluster randomised trials in which groups of subjects are allocated to different treatments are …

Background Prospective cohorts represent an essential design for epidemiological studies
and allow for the study of the combined effects of lifestyle, environment, genetic …

Interactions between parental conditions, environmental exposures and genetic variations
may affect growth, development, plasticity and functioning of parental gametes and …

Many potentially modifiable population factors (BMI, smoking, and environmental
exposures) as well as health system factors (practices related to indicated preterm …

This paper argues that the use of the odds ratio parameter in epidemiology needs to be
considered with a view to the specific study design and the types of exposure and disease …

Random measurement error is a pervasive problem in medical research, which can
introduce bias to an estimate of the association between a risk factor and a disease or make …

The debate concerning the choice of effect measure for epidemiologic data has been
renewed in the literature, and it suggests some continuing disagreement between the …

Conclusions In conclusion, we agree with Rothman and colleagues that scientific inference
does not require representativeness, and often explicitly requires that study samples should …