Ocean offers several 'canned' reports that can give you insight into how many patients are receiving reminders and confirming or cancelling appointments. They provide record level data for the last 60 days that can be exported for analysis. You can access them by logging into the Ocean Portal, clicking on the "Menu" button in the top left corner and selecting "Admin". From the Admin Settings page, click "Reports".
Reports available for Patient Reminders:
Ocean Reminder Sent to Patient - Patients that received a reminder email (whether or not the appointment confirmation feature was enabled)
Ocean Reminder Appointment Confirmed - Patients that confirmed an appointment (only applicable if the Reminder Rule has the 'Appointment Confirmation' setting enabled)