Data transfer and quality review
TRANSFORMATION
For sites participating in the Map-to-CDM and Network Consortium strategies, the coordinating center was able to assess data quality before acquiring the study-specific data. First, for the Map-to-CDM sites, we distributed the existing PCORnet data curation code to query the content of tables formatted according to the CDM. The distributed code generated aggregate output tables that help determine whether the data conformed to specifications, maintained integrity across variables and across tables and trended as expected over time (see The coordinating center then obtained the study-specific data for patients who consented to participate in the demonstration project. For sites participating in the Network Consortium or Map-to-CDM strategy, this was done using standard programs distributed to each study site for execution behind institutional firewalls. For sites participating in the Central Transformation strategy, the study utilized secure mechanisms by which sites sent data extracts of their EHR data in a flat file to the coordinating center for processing. Data received from Central Transformation sites represented all EHR data for the project participants. The coordinating center then transformed these data into the CDM format and performed the same study-specific data quality assessment that were done for the Network Consortium/Map-to-CDM sites. In their initial data submissions, all of the Central Transformation sites had some data quality issues, such as mapping issues and unexpected omissions. The coordinating center collaborated with the sites to help them rectify remediable issues (i.e., issues that were not a reflection of source data limitations). Following receipt and quality assessment of all site data, study data were aggregated and prepared for statistical analysis to support comparison to eCRF and CEC datasets from the trial