Regionalizing mortality data: ischaemic heart disease in Norway

Area of Science:

• Epidemiology
• Biostatistics
• Geographic Information Systems (GIS)

Background:

• Geographical patterns and time trends in cause-specific mortality analysis are sensitive to the chosen regionalization schemes.
• Understanding these patterns is crucial for public health interventions and resource allocation.

Purpose of the Study:

• To explore the impact of different regionalization methods on geographical mortality analysis.
• To investigate geographical time trends in ischemic heart disease (IHD) mortality in Norway from 1970 to 1985.
• To assess the effectiveness of heart disease intervention projects.

Main Methods:

• Development of a geographical mortality information system for Norway using individual death records.
• Application of various regionalization schemes to analyze IHD mortality data.
• Statistical analysis of mortality trends across rural-urban divides and subnational regions.

Main Results:

• A tendency towards regional convergence in IHD mortality was observed in the rural-urban dimension.
• No significant convergence in IHD mortality was found between Norway's five subnational regions.
• No clear evidence emerged that counties with intervention projects fared better than those without, though significant variations existed within intervention areas.

Conclusions:

• The choice of regionalization significantly impacts the interpretation of geographical mortality data.
• While rural-urban mortality trends for IHD showed convergence, subnational disparities persisted.
• Further in-depth analysis is recommended to evaluate the impact of specific heart disease intervention projects.