Bath Ankylosing Spondylitis Disease Activity Index: BASDAI
The BASDAI is a validated diagnostic test and is often used to determine the effectiveness of the drug therapy or to indicate the need for a new drug therapy for the treatment of Ankylosing Spondylitis (AS). 

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Research authors: Garrett S., Jenkinson T., Kennedy L.G., Whitelock H., Gaisford P., Calin A.
Details Formula Study characteristics Files & References
Model author
Model ID
Revision date
MeSH terms
  • Rheumatology
  • Ankylosing Spondylitis
  • Model type
    Custom model (Calculation)

    Additional information

    No additional information available

    Study Population

    Total population size: 0

    Additional characteristics

    No additional characteristics defined
    Bath Ankylosing Spondylitis Disease Activity Index: BASDAI
    Refer to Intended Use for instructions before use
    Evidencio B.V., Irenesingel 19, 7481 GJ, Haaksbergen, the Netherlands

    Your BASDAI score is:

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    Your BASDAI score is: points

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    Outcome stratification

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    Result interpretation

    How this model should be used:
    The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) disease activity questionnaire contains six questions regarding subjective symptoms during the week prior to answering the above six questions.

    Evaluation of model performance:
    The BASDAI was found by patients to be quick and simple to complete (mean: 67 s). Test-retest reliability was good (r = 0.93; p < 0.001), as was the distribution of scores across the scale (score range: 0.5-10; mean: 4.31). BASDAI was sensitive to change, reflecting a 16% (mean) improvement in inpatient scores after 3 weeks of treatment. It is superior to the DAI in terms of construct and content validity and to the Enthesis Index in all aspects.

    Garrett S, Jenkinson T, Kennedy LG, et al. A new approach to defining disease status in ankylosing spondylitis: the Bath Ankylosing Spondylitis Disease Activity Index. J Rheumatol. 1994;21(12):2286-91.

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    Calculations alone should never dictate patient care, and are no substitute for professional judgement. See our full disclaimer.

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