In 2018 R2 we added an interactive user activity log.
You can view changes to your Appointments and Transactions.
This is accessible by right-clicking MediLinkIt in the taskbar notification area, and going to User Activity Logs Appointment Log or Transaction Log.
Note that in some cases your Appointment log may grow very large, and may not load. It may be able to be truncated manually to resolve this (and/or simply a back-up of it made and it emptied out).
Note that for Transactions, in older versions of Medilink only Invoices were logged. This is now changed, but if you are reviewing historic data you will only see some logging - you will have to use the Audit Trail for that.