What does BASFI measure and what is its range?

BASFI measures functional ability in AS using 10 questions (0-10 VAS each); total score is mean of 10 items (0-10); higher = worse function; covers activities like putting on socks, bending, getting up from floor.

How much BASFI improvement is clinically meaningful?

MCID (minimal clinically important difference) is 0.5-1.0 units on 0-10 scale; ASAS 20 includes ≥20% + ≥1 unit improvement in 2 of 4 domains including BASFI; biologic response criterion.

How does BASFI correlate with radiographic damage?

BASFI correlates with cumulative radiographic damage (mSASSS) but also with disease activity; effective biologic therapy improves BASFI independently of structural changes by reducing inflammation and stiffness.

What other functional measures are used alongside BASFI?

BASMI (Metrological Index) measures spinal mobility objectively (tragus-to-wall, lumbar flexion, cervical rotation, lumbar side flexion, intermalleolar distance); BASFI + BASMI comprehensively assess function and mobility.

Is BASFI appropriate for other spondyloarthritides?

BASFI is validated for AS (radiographic axial SpA); it is commonly used in nr-axSpA, PsA, and IBD-related arthritis though validation is less robust; disease-specific PsA measures (PSAID) may be preferred for psoriatic arthritis.

BASFI (Bath Ankylosing Spondylitis Functional Index) Calculator

Calculates BASFI functional disability in ankylosing spondylitis using 10 patient-reported physical function questions on daily activities and ability to cope, tracking functional response to biologic therapy.

Use the full interactive calculator below, or

Related Calculators

BASDAI AS

Hyper-niche Medical

ASDAS-CRP

Medical Calculators

HAQ-DI Score