Enroll-HD: A Prospective Registry Study in a Global Huntington’s Disease Cohort A CHDI Foundation Project

The data collected by the study sites are entered electronically into the Enroll-HD electronic data capture system (EDC) .The system ensures that the format and definitions of data entered are consistent on an intra- and inter-site level, cross-sectionally and longitudinally. EDC updates are performed periodically as controlled and documented releases, following detailed user testing to ensure the data continues to be stored correctly in the updated EDC. To ensure data completeness, the EDC facilitates data collection by presenting all mandatory (core) assessments as mandatory case report forms (CRFs). Dependent on the applicability, all fields within the CRFs are mandatory (e.g., gender is required for all participants, but the number of cigarettes smoked per day is only required for smokers). The system is set up to guide the user to enter all required data. Drop-down menus, help text, and system prompts, as well as linked guidance documents, are also provided next to specific data entry fields to guide data collection and help ensure that the site staff enter the correct information, in the correct format.
To maximise data accuracy at the point of data collection and entry, the EDC contains automated data validity checks (“edit checks”). It imposes data entry thresholds for specific fields, preventing entry of ‘out-of-range’ values (e.g., height of a person cannot exceed 230 cm). The EDC also cross-checks variable field entries within a CRF (e.g., in the motor examination - a large discrepancy between left- and right-hand assessments), across CRFs within the same visit (e.g., discrepancy in assessment of participant capability for employment in two different functional scales), and across visits (e.g., an unreasonable difference between assessments conducted in consecutive years).
The EDC messaging system alerts the data entry person of missing or discrepant entries. When a system alert is activated, the data entry person can choose to change the value, if inco