International spondyloarthritis interobserver reliability exercise--the INSPIRE study: II. Assessment of peripheral joints, enthesitis, and dactylitis.
OBJECTIVE
To determine whether the assessments of peripheral joints and enthesitis were reproducible for both AS and PsA with axial disease, and whether dactylitis assessment is reproducible in patients with PsA.


METHODS
A group of 20 rheumatologists from 11 countries with expertise in spondyloarthritis (SpA) met for a combined physical examination exercise to assess 10 patients with PsA with axial involvement (9 men, 1 woman, mean age 52 yrs, disease duration 17 yrs) and 9 patients with AS (7 men, 2 women, mean age 38 yrs, disease duration 16 yrs). A modified Latin-square design that enabled assessment of patient, assessor, and order effect was used. Measures included were number of tender and swollen joints, presence of enthesitis using 6 different indices, and dactylitis score. Data were analyzed using intraclass correlation (ICC) adjusted for order of measurements.


RESULTS
The majority of the variance was contributed by the patients. There was no order effect. The assessment of tender joints (ICC 0.69) was more reliable than the assessment of swollen joints (ICC 0.54). Moreover, there was better agreement in patients with PsA (ICC 0.78) than in patients with AS (ICC 0.62). There was excellent agreement on the number of active enthesitis sites (ICC 0.86). All the enthesitis indices provided substantial to excellent agreement among observers. Agreement for the dactylitis score was substantial (ICC 0.70).


CONCLUSIONS
The assessment of peripheral joints is more reliable in patients with PsA. Enthesitis instruments can be used reliably in patients with AS and patients with PsA with spinal involvement. The Leeds dactylitis instrument functions well in PsA.
Centre for Prognosis Studies in the Rheumatic Diseases, University of Toronto, Toronto, Ontario, Canada. dafna.gladman@utoronto.ca
Dafna D
DD
Gladman
Robert D
RD
Inman
Richard J
RJ
Cook
Walter P
WP
Maksymowych
Jurgen
J
Braun
John C
JC
Davis
Robert B M
RB
Landewé
Philip
P
Mease
Joachim
J
Brandt
Ruben Burgos
RB
Vargas
Vinod
V
Chandran
Philip
P
Helliwell
Arthur
A
Kavanaugh
Finbar D
FD
O'Shea
Muhammad A
MA
Khan
Nicolo
N
Pipitone
Proton
P
Rahman
John D
JD
Reveille
Millicent A
MA
Stone
William
W
Taylor
Douglas J
DJ
Veale
Desirée
D
van der Heijde
D000328:Adult; D015535:Arthritis, Psoriatic / Q000503:physiopathology; D005260:Female; D005385:Fingers / Q000503:physiopathology*; D006801:Humans; D007596:Joints / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009141:Musculoskeletal System / Q000503:physiopathology*; D015588:Observer Variation; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D025241:Spondylarthritis / Q000503:physiopathology*; D013167:Spondylitis, Ankylosing / Q000503:physiopathology; D014034:Toes / Q000503:physiopathology*