Objectives: implementation and validation of a methodology to link and integrate hospital discharge record (SDO), birth certificate (CeDAP) and the population-based registry of congenital malformations of the Emilia-Romagna Region (IMER). An algorithm has been developed to link registry data and administrative data through the use of indirect patient identifiers in order to exploit the strengths of the different data sources and to expand the pool of existing data available for the analysis.
Design: use of IMER Registry, birth certificates and hospital discharge records to assess and diagnose congenital malformations; these data sources vary in terms of availability and accuracy.
Setting and participants: data from IMER Registry, SDO and CeDAP for year 2009 have been used.
Results: the main results of the study are: 1. a perfect monitoring system does not exist, the algorithm proposed enabled the integration of three different sources and the evaluation of the capacity to identify different anomalies to be capitalized on; 2. the high number of false positives in audit reporting in 4 hospitals underlines the importance of the contribution of clinical experts in the review of the case to exclude coding errors, clarify unspecific diagnostic categories and identify syndromes; 3. the IMER Registry with over 30 years of experience has been the catalyst for this work by integrating clinical skills in the registry with the public health expertise of other professionals involved in information flows; 4. in the absence of a single comprehensive source of data collection, the advantage of the integration of the information collected from multiple sources is confirmed.
Conclusion: birth defects surveillance programmes are critical resources that can provide fundamental information to take sound decisions in healthcare planning and for environmental epidemiology studies. This experience, whilst not mechanically transferable to other areas and circumstances, is a model for the future clinical and epidemiological management of congenital anomalies.