Linking a European cohort of children born with congenital anomalies to vital statistics and mortality records: A EUROlinkCAT study.

EUROCAT is a European network of population-based congenital anomaly (CA) registries. Twenty-one registries agreed to participate in the EUROlinkCAT study to determine if reliable information on the survival of children born with a major CA between 1995 and 2014 can be obtained through linkage to national vital statistics or mortality records. Live birth children with a CA could be linked using personal identifiers to either their national vital statistics (including birth records, death records, hospital records) or to mortality records only, depending on the data available within each region. In total, 18 of 21 registries with data on 192,862 children born with congenital anomalies participated in the study. One registry was unable to get ethical approval to participate and linkage was not possible for two registries due to local reasons. Eleven registries linked to vital statistics and seven registries linked to mortality records only; one of the latter only had identification numbers for 78% of cases, hence it was excluded from further analysis. For registries linking to vital statistics: six linked over 95% of their cases for all years and five were unable to link at least 85% of all live born CA children in the earlier years of the study. No estimate of linkage success could be calculated for registries linking to mortality records. Irrespective of linkage method, deaths that occurred during the first week of life were over three times less likely to be linked compared to deaths occurring after the first week of life. Linkage to vital statistics can provide accurate estimates of survival of children with CAs in some European countries. Bias arises when linkage is not successful, as early neonatal deaths were less likely to be linked. Linkage to mortality records only cannot be recommended, as linkage quality, and hence bias, cannot be assessed.

Coronary heart disease rates within a small urban area in Belgium.

STUDY OBJECTIVE: To identify geographical differences in coronary heart disease (CHD) attack rates in a small urban area and to relate these to indicators of socioeconomic class. DESIGN: CHD attack rates were calculated from data of the Ghent MONICA myocardial infarct register for the period 1983-87. The city of Ghent is subdivided into 201 sectors based on morphological, and socioeconomic characteristics. During the national census of 1981, the main determinants of residential differentiation were measured. These sector variables were linked with the CHD attack rates. PATIENTS: All residents of the city aged 25-69 years are prospectively followed with regard to heart attacks. Between 1982 and 1987, 1728 suffered an acute heart attack according to MONICA criteria. MAIN RESULTS: Significant (p < 0.05) differences in age and sex standarised attack rates were observed between city sectors. These differences were related to an index of socioeconomic status. CONCLUSION: Within a small urban area, significant geographical differences occur in CHD attack rates and these are related to socioeconomic status.