... physical func-tion and disability [21]. The HAQ-DI contains 20 items dividedinto 8 domains that measure dressing and grooming, arising,eating, walking, hygiene, reach, grip, and common daily ... population and wastested against two meaningful clinical changes in patients: theACR20 and the physical functioning (HAQ-DI) response.According to the primary analysis of the FAST 4WARD study,a ... the disciminantvalidity (that is, the ability to differentiate between patients with different RA symptom severity), responsiveness to clinicallymeaningful changes, and reliability of the WPS-RA....