Currently there is not an option to delete notifications. For HIPAA compliance and auditing purposes, we keep track of all past communications.
One thing you can do is contact your office and ask them to update the Notifyd archive period. This setting automatically hides notifications that are older than a specified number of days, and cuts down how much information you're having to manage on your mobile phone.
Our recommendation is to start with 30 days, and see how that works for your company.