In general, we can say, two sets are equivalent to each other if the number of elements in both the sets is equal. And it is not necessary that they have same elements, or they are a subset of each other.
Caregivers must have excellent communication skills, both written and verbal. Even if your client isn't able to communicate through the traditional means of speaking and writing, you'll need to interact with their family members or other caretakers to discuss their care and updates to their condition.