Which method assesses completeness using estimations from an independent survey of cases?

• A. Benchmarking
• B. Independent case ascertainment
• C. Data validation
• D. Reabstraction study

Answer: (B)

Evaluating completeness of case capture is about seeing how many cases a registry might be missing by comparing its counts to an external source that independently identifies cases in the same population. This approach uses an independent survey to enumerate eligible cases, then matches those cases to what the registry has recorded. The difference between the independent count and the registry count provides an estimate of under-ascertainment and the registry’s completeness, guiding improvements in case capture.

Benchmarking compares performance with other registries, data validation checks whether data values are accurate and plausible, and reabstraction studies re-collect data from the original sources to assess data quality (accuracy) rather than completeness.