Validity, reproducibility, and responsiveness of a twelve-joint simplified power doppler ultrasonographic assessment of joint inflammation in rheumatoid arthritis.
OBJECTIVE
To investigate the validity, reproducibility, and responsiveness of a simplified power Doppler ultrasound (PDUS) assessment of joint inflammation compared with a comprehensive 44-joint PDUS assessment in patients with rheumatoid arthritis (RA) who started therapy with a biologic agent.


METHODS
A total of 160 patients with active RA who started a biologic agent were prospectively recruited in 18 Spanish centers. The patients underwent clinical and laboratory assessment and blinded PDUS examination at baseline and 6 months. A PDUS examination of 128 synovial sites in 44 joints was performed. US synovitis and PD signal were semiquantitatively graded from 1 to 3 in all synovial sites. US count and index for synovitis and PD signal were obtained. PDUS intraobserver and interobserver reliability were evaluated. A process of data reduction based on the frequency of involvement of synovial sites by both synovitis and PD signal was conducted. Construct and discriminant validity of a simplified PDUS assessment was investigated.


RESULTS
A PDUS simplified assessment including 24 synovial sites from 12 joints detected 100% of patients with synovitis and 91% of patients with PD signal. There was a highly significant correlation between the 44-joint count and index for synovitis and PD signal and the 12-joint count and index for synovitis and PD signal at baseline and 6 months (r = 0.84-0.90, P < 0.0005). The smallest detectable difference was lower than the mean change in simplified PDUS variables.


CONCLUSIONS
A 12-joint PDUS assessment of RA joint inflammation may be a valid, feasible method for multicenter monitoring of therapeutic response to biologic agents.
Naredo
Esperanza
E
Hospital Severo Ochoa, Madrid, Spain.
Rodríguez
Manuel
M
Campos
Cristina
C
Rodríguez-Heredia
José Manuel
JM
Medina
Julio A
JA
Giner
Emilio
E
Martínez
Olga
O
Toyos
Francisco Javier
FJ
Ruíz
Teresa
T
Ros
Inmaculada
I
Pujol
Manuel
M
Miquel
Xavier
X
García
Luz
L
Aznar
Juan José
JJ
Chamizo
Eugenio
E
Páez
Manuel
M
Morales
Pilar
P
Rueda
Amalia
A
Tuneu
Roser
R
Corominas
Hector
H
de Agustín
Juan José
JJ
Moragues
Carmen
C
Mínguez
Dolores
D
Willisch
Alfredo
A
González-Cruz
Isabel
I
Aragón
Angel
A
Iglesias
Gerardo
G
Armas
Carlos
C
Pablo Valdazo
Juan
J
Vargas
Carmen
C
Calvo-Alén
Jaime
J
Juan-Mas
Antonio
A
Salvador
Georgina
G
Puigdollers
Angels
A
Galíndez
Eva
E
Garrido
Noemi
N
Salaberri
José
J
Raya
Enrique
E
Salles
Meritxell
M
Díaz
César
C
Cuadra
José Luis
JL
Garrido
Jesús
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001168:Arthritis / Q000000981:diagnostic imaging; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D018608:Ultrasonography, Doppler