The two risk tools studied, based on non-genetic markers, performed better than genotype based tests despite the fact that the models, which were developed in different datasets, were not specifically recalibrated for the Whitehall II population. The common diabetes associated single nucleotide polymorphisms we studied might have greater incremental value in the prediction of type 2 diabetes when evaluated against some of the other validated risk models. However, we chose the Framingham and Cambridge risk scores because they are contemporary (which could be important, given the recent increase in the incidence and prevalence of type 2 diabetes), were developed in populations with a similar profile to the Whitehall II participants, and were based on studies set in the United States and the UK, where many of the genetic studies were done. Moreover, both include variables that are routinely measured in clinical practice. We did not evaluate QDRisk, which is based on routinely collected primary care data (including deprivation scores, ethnicity, and current drug treatment for hypertension or cardiovascular disease and corticosteroid use), which was reported during the preparation of this manuscript.47
