Syddansk Universitet Quality assurance of the Western Denmark heart registry, a population-based healthcare register Rasmussen,

IntroductIon: During the past decade, the mandatory population-based healthcare database, the Western Denmark Heart Registry (WDHR), has provided the data for several research projects. As in most clinical registries, the data quality has not been validated thoroughly. This study was undertaken to evaluate the quality of registrations in the WDHR. Methods: The audit supervised procedures from involved departments that were performed in 2013. An experienced research nurse completed data collection and an experienced consultant evaluated the agreement between the WDHR and patient records. Indistinct data from patient records were determined after consulting a specialist from the department in question. Patient files were doublechecked in case of disagreements between the involved systems. results: The total proportion of errors in the referral date was 16.4% in surgery, 9.8% in percutaneous invasive procedures (PCI), 16.1% in coronary angiography (CAG) and 19.5% in computed tomography (CT)-CAG, while the errors in in-hospital dates were slightly lower. In the cardiac surgery registries, the proportion of errors was 3.3% in the history and EuroSCORE module, 1.0% in the procedure module and 2.8% in the discharge module. For PCI procedures, the errors were 3.8% in the history module, 2.2% in the procedure module and 1.6% in the discharge module. CAG and CTCAG had slightly more errors. conclusIons: The quality control of the WDHR revealed that overall data errors were lower than 3% and for procedure-specific registrations including indications and complications, the error rate was below 1.5%. The WDHR is valid and may be used in contemporary epidemiological studies. FundIng: none. trIal regIstratIon: not relevant. Clinical databases are important tools in quality assurance, treatment development and research. In 1993, the Danish Health Authority initiated the implementation of a national Heart Plan [1] to improve the treatment quality of cardiac diseases. Subsequently, a national heart register and the Western Denmark Heart Registry (WDHR) were established in 1999. Selected variables in the WDHR and a comparable database covering Eastern Denmark are transferred to the national Danish Heart Registry. The WDHR includes data on all adult patients in Western Denmark referred for coronary angiography (CAG), percutaneous coronary intervention (PCI) or cardiac surgery [1]. From 2008, computed tomography coronary angiography (CT-CAG) has also been included. The WDHR covers the entire population of Western Denmark, approximately 3.0 million inhabitants, and is financed by the public owners. Owing to the use of the unique Civil Personal Registration (CPR) number [2] assigned to all Danish citizen and immigrants, it is possible to perform record linkage at the individual level across all Danish health registries [3, 4] and to obtain information on hospital admissions [5], causes of death [6] and prescribed medications [7]. The CPR system has kept records on gender, date of birth, residence, emigration date and vital status changes since 1968. Thus, Denmark has optimal opportunities for conducting registry-based research. This is further strengthened by equal access to treatment, as the Danish health service provides taxfinanced universal healthcare to all Danish citizens guaranteeing free access to care at general practitioners and hospitals [1-3]. The WDHR collects referral and anamnestic information, procedural information like the use of contrast and devices (balloons, stents) in PCI, grafts, valve types, anaesthesia and intensive care together with registration of complications. The WDHR has been the source of a comprehensive number of research projects within cardiology [8-10], cardiac surgery [11-13] and anaesthesiology [14-16], amounting to approximately 50 peer-reviewed publications. The purpose of the present study was to audit the quality of the data registered in the WDHR. mEthOds structure and data quality enforcement Data regarding cardiac surgery originates from three departments, CAG from eight departments, PCI from three departments and CT-CAG from six departments. One private hospital contributes with very few procedures and was not included in the audit. Quality assurance of the Western denmark heart Registry, a population-based healthcare register Linda Aagaard Rasmussen1, Hans Erik Bøtker2, Lisette Okkels Jensen3, Jan Ravkilde4, Lars Riber5, Per Hostrup Nielsen6, Jan Jesper Andreasen7 & Carl-Johan Jakobsen1