Systemic lupus international collaborating clinics renal activity/response exercise: comparison of agreement in rating renal response.
OBJECTIVE
To assess the degree to which physicians agree with each other and with ratings obtained with 3 existing responder indices, in rating the response to treatment of lupus nephritis.


METHODS
Lupus nephritis patient medical records from 125 pairs of visits (6 months apart) were used to create renal response scenarios. Seven nephrologists and 22 rheumatologists rated each scenario as demonstrating complete response, partial response, same, or worsening. The plurality (most frequent) rating of renal response by the physicians was compared with the calculated score from the renal component of the British Isles Lupus Assessment Group (BILAG) index (original and updated [2004] version) and of the Responder Index for Lupus Erythematosus (RIFLE). The degree of agreement among the physicians was assessed by calculating intraclass correlation coefficients (ICCs). The degree of agreement between the plurality physician rating and ratings obtained with the established response indices was assessed using the kappa statistic.


RESULTS
The ICC among all physicians was 0.64 (0.62 for nephrologists and 0.67 for rheumatologists). The chance-adjusted measure of agreement (kappa coefficient) between the plurality physician rating and the calculated score obtained using established indexes was 0.50 (95% confidence interval [95% CI] 0.38-0.61) for the RIFLE, 0.14 (95% CI 0.03-0.25) for the original BILAG, and 0.23 (95% CI 0.21-0.44) for the BILAG 2004.


CONCLUSIONS
These findings indicate that rheumatologists as a group and nephrologists as a group have equal agreement in their rating of renal response. There was moderate agreement between plurality physician ratings and ratings obtained using the renal component of the RIFLE. Ratings of response using an index based on the original BILAG did not have good agreement with the plurality physician rating.
Department of Rheumatology, Johns Hopkins University, Baltimore, Maryland 21205, USA. mpetri@jhmi.edu
Michelle
M
Petri
Nuntana
N
Kasitanon
Sukminder
S
Singh
Kimberly
K
Link
Laurence
L
Magder
Sang-Cheol
SC
Bae
John G
JG
Hanly
Ola
O
Nived
Gunnar
G
Sturfelt
Ronald
R
van Vollenhoven
Daniel J
DJ
Wallace
Graciela S
GS
Alarcón
Dwomoa
D
Adu
Carmen
C
Avila-Casado
Sasha R
SR
Bernatsky
Ian N
IN
Bruce
Ann E
AE
Clarke
Gabriel
G
Contreras
Derek M
DM
Fine
Dafna D
DD
Gladman
Caroline
C
Gordon
Kenneth C
KC
Kalunian
Michael P
MP
Madaio
Brad H
BH
Rovin
Jorge
J
Sanchez-Guerrero
Kristjan
K
Steinsson
Cynthia
C
Aranow
James E
JE
Balow
Jill P
JP
Buyon
Ellen M
EM
Ginzler
Munther A
MA
Khamashta
Murray B
MB
Urowitz
Mary Anne
MA
Dooley
Joan T
JT
Merrill
Rosalind
R
Ramsey-Goldman
Josef
J
Font
James
J
Tumlin
Thomas
T
Stoll
Asad
A
Zoma
D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000503:physiopathology*; D008181:Lupus Nephritis / Q000175:diagnosis*; D009398:Nephrology / Q000592:standards*; D015588:Observer Variation; D012219:Rheumatology / Q000592:standards*; D012720:Severity of Illness Index