Final answer:
The most important instruction for the nurse to include when preparing a client with a flare of rheumatoid arthritis for discharge is to take prescribed cortisone accurately.
Step-by-step explanation:
The most important instruction for the nurse to include when preparing a client with a flare of rheumatoid arthritis for discharge is to take prescribed cortisone accurately. Cortisone, also known as corticosteroids, is a medication commonly used to reduce inflammation and pain in rheumatoid arthritis. It helps control the symptoms and manage the disease. It is important to take cortisone as prescribed by the healthcare provider to ensure its effectiveness.