Calin et al developed the Bath Ankylosing Spondylitis Functional Index (BASFI) to describe the disease activity for a patient with ankylosing spondylitis. The authors are from Royal National Hospital for Rheumatic Diseases in Bath, England.
Activities performed during the last week:
(1) ability to put on socks or tights without help or use of aids
(2) ability to bend forward at the waist to pick up a pen from the floor without an aid
(3) ability to reach up to a high shelf without help or aids
(4) ability to get up from an armless dining room chair without using hands, help or an aid
(5) ability to get up off the floor from lying on your back without help or an aid
(6) ability to stand unsupported for 10 minutes without discomfort
(7) ability to climb 12-15 steps one step at a time without using a handrail or walking aid
(8) ability to look over your shoulder without turning your body
(9) ability to do physically demanding activities (e.g., physiotherapy exercises, gardening or sports)
(10) ability to do a full day's activities whether it be at home or at work
where:
• An aid is a piece of equipment that helps a person to perform an action or movement.
Scoring:
(1) linear distance along a 10 cm visual analogue scale (VAS), anchored at easy (0 cm) to impossible (10 cm)
(2) 11 boxes ranging from easy (0) to impossible (10)
sum of items =
= SUM(points for all 10 items)
BASFI =
= MEAN(10 items) = (sum of items) / 10
Interpretation:
• minimum index: 0
• maximum index: 10
• The higher the index the more severe the disease (greater disease activity).
Performance:
• The index is quick and easy to complete, shows good reliability, and is sensitive to changes across the whole spectrum of ankylosing spondylitis.
