Determination of Relative Weightings for Sacroiliac Joint Pathologies in the OMERACT Juvenile Arthritis Magnetic Resonance Imaging Sacroiliac Joint Score.

2023

04/2023

2077-0383

This study aims to determine the relative weights (point value) of items of the juvenile idiopathic arthritis magnetic resonance imaging-sacroiliac joint scoring system (JAMRIS-SIJ). An adaptive multicriteria decision analysis was performed using the 1000Minds web application to determine the relative weights of the items in the JAMRIS-SIJ inflammation and damage domains. Experts in imaging and rheumatology independently completed a conjoint analysis survey (CAS) to determine the point value of the measurement items of the JAMRIS-SIJ. Each CAS survey question asked the expert to compare two hypothetical patient profiles, which were otherwise similar but different at two items at a time, and to select which item showed a more severe stage of inflammation or osteochondral damage. In addition, experts ranked 14 JAMRIS-SIJ grade only or image + grade patient vignettes while blinded to the CAS-derived weights. The validity of the weighted JAMRIS-SIJ was tested by comparing the expert CAS-weighted score and the image + grade ranking method. Seventeen experts completed the CAS (11 radiologists and 6 rheumatologists). Considering the point value for inflammation domain items, osteitis (24.7%) and bone marrow edema (24.3%) had higher group-averaged percentage weights compared to inflammation in erosion cavity (16.9%), joint space enhancement (13.1%), joint space fluid (9.1%), capsulitis (7.3%), and enthesitis (4.6%). Similarly, concerning the damage domain, ankylosis (41.3%) and erosion (25.1%) showed higher group-averaged weights compared to backfill (13.9%), sclerosis (10.7%), and fat metaplasia lesion (9.1%). The Spearman correlation coefficients of the CAS-weighted vignette order and unweighted JAMRIS-SIJ grade only order vignettes for all experts were 0.79 for inflammation and 0.80 for damage. The correlations of image vignettes among imaging experts to CAS were 0.75 for inflammation and 0.90 for damage. The multicriteria decision analysis identified differences in relative weights among the JAMRIS-SIJ measurement items. The determination of the relative weights provided expert-driven score scaling and face validity for the JAMRIS-SIJ, enabling the future evaluation of its longitudinal construct validity.

10.3390/jcm12072729

J Clin Med

37048812

Consensus-driven definition for unequivocal sacroiliitis on radiographs in juvenile spondyloarthritis.

2023

04/2023

0315-162X

OBJECTIVE: Radiography is still used worldwide for detection of sacroiliitis in juvenile spondyloarthritis (SpA), despite low sensitivity and reliability. We aimed to define unequivocal evidence of sacroiliitis on pelvic radiography in skeletally immature youth for use in classification criteria when MRI is unavailable.

METHODS: Subjects were a retrospective cohort of juvenile spondyloarthritis (SpA) patients with a radiograph and MRI as part of a diagnostic evaluation for axial disease. Six musculoskeletal imaging experts underwent an iterative consensus process to define "unequivocal sacroiliitis" on radiography in skeletally immature youth. Radiographs were graded using the modified New York (mNY) criteria and the unequivocal sacroiliitis criteria. Interrater agreement was assessed with Fleiss' kappa statistic. Specificity, area under receiver operator characteristic (AUROC), and sensitivity of the two measures were tested using 2 MRI reference standards.

RESULTS: 112 subjects, median age 14.9 years were included. Fleiss' kappa was fair for the mNY [0.51 (95% CI: 0.39-0.64)] and unequivocal sacroiliitis criteria [0.55 (95% CI: 0.43-0.66)]. The unequivocal sacroiliitis criteria achieved >90% specificity using both MRI reference standards. Sensitivity (59.26/57.14 vs 44.83/43.33) and AUROC (0.76/0.76 versus 0.71/0.71) were higher, for both reference standards, for the unequivocal sacroiliitis in youth definition than the mNY criteria, respectively.

CONCLUSION: We propose the first consensus-derived definition of unequivocal sacroiliitis by radiography in skeletally immature youth. This definition achieved excellent specificity and had higher AUROC and sensitivity than the mNY criteria using both MRI reference standards. This definition has applicability to juvenile SpA axial disease classification imaging criterion when MRI is unavailable.

10.3899/jrheum.2022-0890

J Rheumatol

37061228