Existing data sources for clinical epidemiology: The Western Denmark Heart Registry

Background: The Western Denmark Heart Registry (WDHR) has not previously been described as a research tool in clinical epidemiology.

Objectives: We examined the setting, organization, content, data quality, and research potential of the WDHR.

Method: We collected information from members of the WDHR organization, including the committee of representatives, the board, the data management group, and physicians reporting to the database. We retrieved 2008 data from the WDHR to illustrate database variables.

Results: The WDHR is a clinical database within a population-based health care system. It was launched on 1 January 1999 to monitor and improve the quality of cardiac intervention in Western Denmark (population: 3.3 million) and to allow for clinical and health-service research. More than 200,000 interventions, with 50-150 variables each, have been registered. The data quality is ensured by automatic validation rules at data entry combined with systematic validation procedures and random spot-checks after entry.

Conclusions: The WDHR is a valuable research tool because it provides ongoing longitudinal registration of detailed patient and procedural data. The Danish national health care system enables this research because it allows complete follow-up for medical events after cardiac intervention by linkage with multiple medical databases.