Registry studies and post-marketing surveillance

Summary

A clinical quality registry systematically collects clinical data for the assessment of how medical care is provided and to what extent international or local guidelines are followed in order to improve quality of care. Collection of outcome variables is of utmost importance to evaluate temporal trends and the effects of changes of treatment alternatives. Of particular interest and importance are the collection of complication rates and side effects of novel pharmaceutical agents, medical devices or new treatment strategies used in clinical practice, often beyond the original indications studied in inceptional randomised studies. While prospective randomised trials provide the highest level of scientific evidence, they are often limited by including selected populations and are expensive to perform. Observational studies from well-developed registries are inexpensive and relatively simple to perform. Therefore, observational studies from large-scale registries are valuable complements to prospective randomised trials. However, an inherent disadvantage is the limited ability to independently adjudicate endpoints. Hence total mortality is the most reliable hard endpoint for these studies. Despite appropriate statistical methodologies to adjust for differences in baseline characteristics, there are always known and/or hidden confounders that cannot be completely compensated. Therefore, it is important to be cautious in the interpretation of observational...