Characteristics of the InterAct incident cases are described using summary statistics (means, standard deviations, frequencies and percentages) separately for men and women, and overall. Characteristics of the randomly selected subcohort are also summarised, alongside summaries from the overall EPIC cohort from which it was sampled, to provide some indication of the representativeness of the subcohort compared with the whole of EPIC. Comparison p-values were not calculated for these two groups, as due to the large sample size, even very small, clinically negligible differences in the distribution of a particular characteristic are likely to be statistically significant. Prentice-weighted Cox regression models and random effects meta-analyses were used, as described in more detail in the online appendix (supplementary methods), to investigate differences in the incidence of diabetes by sex and age. Crude and age-standardised incidence rates were calculated within each country.
