Background: Previous research revealed substantial differences in mortality due to ischemic heart disease (IHD) between the 16 German states. As variation may also be present within these states, analyses with higher geographical resolution are necessary to characterize changes in the magnitude of variation over time.
Aim: To describe regional differences of IHD mortality in Germany over a period of 10 years (1998 and 2007) on a county level and to investigate whether variation in mortality can be explained by region.
Methods: Data on deaths due to IHD (ICD 10 I20-I25) and the number of inhabitants were obtained from the State Offices for Statistics to calculate age-standardized rates. Poisson regression models with and without random effects and measures of absolute variability (standard deviation) and relative variability (coefficient of variation) were used to analyze mortality due to IHD.
Results: Regional differences in IHD mortality were observed (p < 0.001) with the highest burden in the northeast and the lowest in the southwest. From 1998 to 2007, age-standardized mortality rates due to IHD decreased by >35% in men and women (p < 0.001). While measure of absolute variability between German regions also decreased by >35% (p < 0.001), measures of relative geographical differences did not change in men (-2.5%, p = 0.618) and decreased only slightly in women (-10.2%, p = 0.044).
Conclusion: There is a marked regional variation of IHD mortality in Germany. The relative variability changed little during the last 10 years and provides a unique chance to characterize the impact of important IHD risk factors on the population level and improve preventive strategies.