Imagine this. A well credentialed caregiver shows up at a new client and is briefed at length by the previous caregiver, who is leaving. This new caregiver listens to everything without making any notes at all on this complex case. She is there, her first day, without the thought of keeping a notebook! I actually recommend....keeping two books. One, a professional diary of client vital signs, medications, exercise, therapy, and other relevant information. The data included should be specific to that client's condition. Notes should be professional and factual. So often, caregiver diaries are either irregular and disorganized, or interesting to read but not particularly useful.
This notebook is for professional use, and should be treated as confidential for the client. In keeping it, though, we should consider that if there is an emergency of some kind, we would want to be able to retrace everything that might be relevant for the attending physicians.
Secondly, a condensed notebook to bring to routine doctors' appointments. Ask the client's doctors what they would like to see in this book, and remember that they will want to scan it easily from the previous appointment for pertinent data. They won't want a lot of commentary. Some specialists have their own format that they like to see used.
Don't forget. Update the notebooks on a regular daily schedule, while the day's activities are still fresh.