Figure 2

Ratios of incidence rates in Varna rural and urban populations and in Novosibirsk (Russia) to the unweighted average of rates for 9 western populations (used as reference) [12]. Comparisons are made separately for two age bands, 45 to 64 and 65 to 84 with the rates for the bands being first calculated as the unweighted averages of contributory sex and age specific rates. 95% confidence intervals are calculated on the assumption that the reference rates are free of sampling variance.