Which type of casefinding is performed by registry personnel who screen the source documents themselves?

Active casefinding involves registry personnel actively searching for cases by screening source documents, such as pathology reports, radiology reports, surgical notes, and other clinical documents. This method requires direct engagement with the medical records to identify any potential cancer cases. The goal of active casefinding is to ensure that all eligible cases are captured and accurately reported to the cancer registry, enhancing the completeness and quality of cancer data.

In contrast, passive casefinding relies on other sources to report cases, such as receiving information from hospitals or physicians without the registry actively investigating the source documents. Rapid case ascertainment refers to a more urgent collection of data, typically during a specific time frame for a public health response, rather than ongoing surveillance.

Thus, the correct answer reflects the proactive nature of active casefinding where registry personnel directly engage with source documents to identify and document cancer cases.