Rheumatology
The BASDAI is a patient-reported index, historically widely used to quantify the symptomatic activity of axial spondyloarthritis. It assesses fatigue, axial and peripheral pain, tenderness to pressure, and morning stiffness. Its calculation does not correspond to the simple raw average of the six responses.
Number of questions
6 items
Approximate duration
2 to 4 minutes
Population
Adults with axial spondyloarthritis
Modality
self-assessment questionnaire
QuestionnaireBASDAI
SELF-QUESTIONNAIRE
On a 0–10 scale, for the official reference period. Reference period: the past week. Question 6: duration of morning stiffness, from 0 to 120 minutes, converted to 0–10 using min(duration in minutes, 120) / 12; 120 minutes or more = 10. An entry already on a 0–10 scale must not be converted a second time.
Are you patient?
Yes. The BASDAI captures how you perceive your symptoms. It does not replace lab tests, physical examinations, or other disease activity scores used by your rheumatologist.
Terms of contract
Self-administered questionnaire completed by the patient alone, referring to the past week. For each question, select a single response that reflects the average level despite fluctuations; the duration of morning stiffness is recorded on the scale provided by the instrument. Use the same format (10 cm line or numerical rating scale) from one assessment to the next.
Score interpretationBASDAI
Average of responses 5 and 6 on morning stiffness, added to the sum of responses 1 to 4, then dividing the total by 5; result from 0 to 10.
Total score
First reading
0
to
3.99
Score below the historical benchmark of 4/10.
4
to
10
Score ≥ 4/10 approximately: historical landmark of significant activity.
≥ approx. 4/10: historical benchmark for significant activity, to be interpreted as a continuous, longitudinal measure.
The BASDAI can be influenced by non-specific symptoms and does not, on its own, distinguish active inflammation from other causes of pain or fatigue.
Frequently asked questions
Why does the question about stiffness count twice?
Are BASDAI and ASDAS equivalent?
What are its limitations?
Sources and references
Andrei Calin and coworkers
Garrett S et al., J Rheumatol, 1994
In practice
Full name
Bath Ankylosing Spondylitis Disease Activity Index
Method
self-assessment questionnaire
Language
French (validated version)
Authors
Andrei Calin and coworkers
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