Even though we cannot randomise individuals to genomic patterns, randomised trials have an important place in enhancing genetic and molecular epidemiology efforts.
First, novel discoveries and technologies of the ‐omics era need to be tested in randomised trials before introduction into clinical and public health use. Discoveries pertaining to diagnosis and disease prediction should show convincing evidence that they can improve outcomes in target populations. These trials may have to wait until we have biomarkers offering incremental advantages over routine diagnostic and predictive tools.21,22
Study design and selection of outcomes requires imaginative thinking, and may have to encompass hard outcomes, quality of life, utilisation of medical treatment and services and cost. Contrasts need to offer control groups the opportunity to obtain the full benefits of standard (non‐molecular) diagnostic or predictive procedures and information.
Randomised trials may have a particularly important role in pharmacogenomic research, where appropriate randomised designs can maximise power and efficiency.23
This may eventually facilitate individualised treatment choices.
We should also seriously consider the introduction of randomised trials nested into large biobanks. Biobanks represent the new generation of cohorts. Nested randomised trials would benefit from routinely using the data machinery of biobanks with linkage to existing registries for death and other hard outcomes (eg, cancer, coronary artery disease, end‐stage renal failure) and practically “unlimited” follow‐up. Tested interventions may pertain both to lifestyle changes and medical drugs or technology. Traditional long‐term trials outside biobanks have become prohibitively expensive and difficult to conduct. With appropriate collection and storage of biological samples, markers can be measured on these samples. This could include markers currently unknown which may be identified and routinely measured in the future. This information may be used to identify treatment–effect modifications based on genetic variants and genetic effects that manifest under specific lifestyle exposures or other interventions.