CCDM Data Standards & Database Design 4 — Questions and Answers
Question 1: Which database design approach stores each attribute of an entity in a separate row rather than separate columns?
- Relational model
- Entity-Attribute-Value (EAV) model (Correct answer)
- Star schema model
- Hierarchical model
Correct answer: Entity-Attribute-Value (EAV) model
The Entity-Attribute-Value (EAV) model uses rows to represent attribute-value pairs, which is flexible for variable data structures but can complicate querying.
Question 2: When a clinical database undergoes a mid-study amendment to add a new data field, what is the MOST critical first step?
- Immediately update the production database schema
- Assess impact on existing data, edit checks, and downstream derivations, then follow change control procedures (Correct answer)
- Notify all sites to begin collecting the new data immediately
- Archive the current database before making any changes
Correct answer: Assess impact on existing data, edit checks, and downstream derivations, then follow change control procedures
A formal impact assessment followed by change control procedures ensures that amendments are implemented without introducing inconsistencies or data integrity issues.
Question 3: In SDTM, what is the --TESTCD variable used for?
- A code representing the type of test or measurement collected (Correct answer)
- The result of a clinical test
- The date a test was performed
- A flag indicating whether a test was performed
Correct answer: A code representing the type of test or measurement collected
--TESTCD is a short character code identifying the specific test or finding (e.g., 'SYSBP' for systolic blood pressure) within findings domains.
Question 4: What is the purpose of a 'data freeze' in clinical data management?
- Permanently deleting all records from the database
- Locking the database at a defined point so no further changes can be made to data included in analysis (Correct answer)
- Archiving old data to offline storage to free server space
- Preventing new subjects from being enrolled in the study
Correct answer: Locking the database at a defined point so no further changes can be made to data included in analysis
A data freeze locks the database at a specific point in time, ensuring that the dataset used for statistical analysis remains unchanged.
Question 5: Which of the following BEST describes a 'derived variable' in an ADaM dataset?
- A variable collected directly on the CRF and stored unchanged
- A variable calculated or transformed from collected or other derived data using documented, reproducible rules (Correct answer)
- A variable imported from an external laboratory vendor file
- A variable that stores the audit trail timestamp
Correct answer: A variable calculated or transformed from collected or other derived data using documented, reproducible rules
Derived variables in ADaM are computed from raw or other derived data using pre-specified, documented algorithms to support analysis.
Question 6: A sponsor uses WHODRUG for coding study medications. What does WHODRUG primarily provide?
- Standardized coding for adverse events and medical history
- A global drug dictionary for identifying and coding medicinal products (Correct answer)
- Laboratory normal reference ranges for common analytes
- Device and equipment classification for medical devices
Correct answer: A global drug dictionary for identifying and coding medicinal products
WHODRUG is a global drug dictionary maintained by the Uppsala Monitoring Centre, used to code and standardize concomitant and prior medication data.
Question 7: In the context of database validation, what is a 'data completeness check'?
- Verifying that all expected records and required fields are present and populated (Correct answer)
- Checking that all numeric values fall within acceptable physiological ranges
- Confirming that adverse events are correctly coded to MedDRA
- Ensuring that the database has no duplicate primary keys
Correct answer: Verifying that all expected records and required fields are present and populated
A data completeness check verifies that all required data points specified in the protocol are present in the database with no unexpected missing values.
CCDM Data Standards & Database Design 4
Which database design approach stores each attribute of an entity in a separate row rather than separate columns?