To describe the natural history of a condition or disease. To describe the natural history of a condition or disease. To determine effectiveness or cost effectiveness of treatments/services and/or health care products. To measure or monitor safety and harm. To measure quality of care.
According to the NMSS, attacks or flare-ups of symptoms only qualify as exacerbations if: 1  they occur at least 30 days from an earlier flare-up. 2  symptoms last for 24 hours or longer.
YOU MIGHT BE EXPERIENCING A RELAPSE, AND YOU SHOULD CALL YOUR DOCTOR, IF: You have new MS symptoms or your existing MS symptoms suddenly become worse. These symptoms last for at least 24 hours (they may go on for days or weeks) Your symptoms occur at least 30 days after your last relapse. You donât have a fever, illness, or similar condition when the symptoms start.