RT Journal Article
SR Electronic
T1 Comparison of the Bath Ankylosing Spondylitis Disease Activity Index and a modified version of the index in assessing disease activity in patients with ankylosing spondylitis without peripheral manifestations
JF Annals of the Rheumatic Diseases
JO Ann Rheum Dis
FD BMJ Publishing Group Ltd and European League Against Rheumatism
SP 1701
OP 1707
DO 10.1136/ard.2008.099226
VO 68
IS 11
A1 I H Song
A1 M Rudwaleit
A1 J Listing
A1 J Sieper
YR 2009
UL http://ard.bmj.com/content/68/11/1701.abstract
AB Objective: To compare the original Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) with a modified BASDAI without questions about peripheral arthritis (question 3) and enthesitis (question 4), here termed the mini-BASDAI, as an instrument to assess disease activity in patients with ankylosing spondylitis (AS) without peripheral manifestations.Methods: The mini-BASDAI was calculated by omitting questions 3 and 4. The correlation of the original BASDAI and the mini-BASDAI with patient global and other disease parameters was assessed in a total of 692 patients from three AS cohorts including one observational AS cohort and two clinical trial populations treated with non-steroidal anti-inflammatory drugs and tumour necrosis factor alpha inhibitors. Sensitivity to change was assessed by calculating effect sizes.Results: Up to 70% of AS patients did not have peripheral involvement. Patients with peripheral involvement had higher disease activity in all activity parameters. The mini-BASDAI had higher values compared with the original BASDAI, also in the subgroup with peripheral manifestations. However, the mini-BASDAI did not correlate better with other markers of disease activity compared with the original BASDAI. Furthermore, effect sizes of the original BASDAI and mini-BASDAI were comparable in the treatment trials. Interestingly, approximately 5% of active AS patients with pure axial disease manifestation were identified whose disease activity was underestimated by the original BASDAI.Conclusion: On a group level using the mini-BASDAI did not result in an advantage to assess disease activity or in the subgroup without peripheral involvement. In only approximately 5% of AS patients was the mini-BASDAI superior to the original BASDAI.