Castor-integration.md

@@ -30,6 +30,12 @@ PEP imports data for individual Castor (CRF) [steps](https://helpdesk.castoredc.
 
 An equivalent principle applies to the import of Castor survey data: answers to a single survey step end up in a single PEP column. Surveys should therefore also be configured in such a way that their data are chunked appropriately.
 
+## Reports imported together
+
+When a CRF contains a repeated measurement question, Castor stores the associated answers in *reports*, with each report containing the answers for a single measurement. When PEP imports such CRF data, all reports associated with the (repeated measurement-type) question are included with the step containing the question. For example, if a subject takes four types of medication, these would be registered as four entries into a repeated measurement question. Castor would store these as four separate reports. When PEP imports the CRF step containing the repeated measurement question, it also includes all answers entered into all four reports.
+
+When PEP is configured to import (only) reports from a Castor study, it puts the answers to all reports of all types into a single column.
+
 ## Data format
 
 Castor data are stored in PEP as JSON: [a data format](https://www.json.org/) that associates keys with values. PEP stores Castor data as a top level JSON node with sub-nodes named `crf` and `reports`.