Bath Ankylosing Spondylitis
Disease Activity Index

Copyright 2005

If you have been diagnosed
with Ankylosing Spondylitis

Rate the Effectiveness of your Treatment

nkylosing Spondylitis is one of the Immune Mediated Inflammatory Diseases or (IMID). More information on Ankylosing Spondylitis is found here. The Study of inflammation offers a wealth of opportunities for impacting biomedical research and health care because inflammation mediates and is the primary driver of many diseases, including Ankylosing Spondylitis, arthritis, autoimmune diseases and allergy, as well as many of the cardiovascular, neuromuscular, and infectious diseases.
progression of ankylosing spondylitis
Little H. et al. Am J. Med 1976;60:279-285

The gold standard for measuring and evaluating disease activity in Ankylosing Spondylitis is the BASDAI, or the Bath Ankylosing Spondylitis Disease Activity Index. The BASDAI is the result of the work of a research team consisting of rheumatologists, physiotherapists, and research associates with a special interest in AS who developed the index in Bath, England. The BASDAI consists of a one through 10 scale (one being no problem and 10 being the worst problem) which is used to answer 6 questions pertaining to the 5 major symptoms of AS:

  • Fatigue
  • Spinal pain
  • Joint pain / swelling
  • Areas of localized tenderness (also called enthesitis, or inflammation of tendons and ligaments)
  • Morning stiffness duration
  • Morning stiffness severity
To give each symptom equal weighting, the mean (average) of the two scores relating to morning stiffness is taken. The resulting 0 to 50 score is divided by 5 to give a final 0 10 BASDAI score. Scores of 4 or greater suggest suboptimal control of disease, and patients with scores of 4 or greater are usually good candidates for either a change in their medical therapy or for enrollment in clinical trials evaluating new drug therapies directed at Ankylosing Spondylitis. More information for physicians regarding tools to measure AS are presented.

When evaluated using strict clinical paramaters, the BASDAI was validated:

  • BASDAI is a quick and simple index (taking between 30 secs and 2 mins to complete)
  • BASDAI demonstrated statistically significant (p<0.001) reliability.
  • BASDAI encorporates a reasonable scale. The individual symptoms and the index as a whole demonstrated good score distribution, using 95% of the scale.
  • BASDAI demonstrates a sensitivity to change within a short period of time. Following a 3 week physiotherapy course, the BASDAI showed a significant (p=0.009) 16.4% score improvement.

View BASDAI printable document (pdf )

(1) Garrett et al, J. Rheumatol 1994;21:2286-91;
(2) Andrei Calin Bio: Andrei Calin, MD, FRCP.

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