Using primary care electronic health record data for comparative effectiveness research: experience of data quality assessment and preprocessing in The Netherlands

Details of data quality and how quality issues were solved have not been reported in published comparative effectiveness studies using electronic health record data. We developed a conceptual framework of data quality assessment and preprocessing and apply it to a study comparing angiotensin-converting enzyme inhibitors with angiotensin receptor blockerss on renal function decline in diabetes patients. The framework establishes a line of thought to identify and act on data issues. The core concept is to evaluate whether data are fit-for-use for research tasks. Possible quality problems are listed through specific signal detections, and verified whether they are true problems. Optimal solutions are selected for the identified problems. This framework can be used in observational studies to improve validity of results.