Thanks Eric for the Reply.

Purpose of tracking Patient Ids : Application being developed is used to track steps in a patient treatment planning workflows, hence for auditing it is required that event being executed be linked to a patient. There can be multiple patients who might be undergoing same treatment workflow steps.

1. Yes I know I can create user events but the question is which already existing attribute of the audit log is efficient to record patient ID's  ? considering  user event created will have same attribute structure 

Example : If I have user   defined"event" Medical record with "event type" as create , edit , approve, view , cancel etc. then Is it a good idea to track Patient ID's , workflow ID in attribute "event data" ? I would not prefer to create a new attribute (column) to track patient ID's , not sure if that is good practise ?

2. Specific use case is that I should be able filter and see auditable events for a specific patient, which is part of patients treatment history. 

3. Also patient information might be subjected data privacy regulation so I am looking into possibilities  of configuration (enable /disable patient id's) of  anonymizing and deanonymizeing patient ID's but yet be  able to track the event.