Table 1.

Demographic and clinical features of patients from both the Israeli and the US cohorts upon presentation

Characteristic	All subjects (n = 87)	Israeli cohort (n = 39)	US cohort (n = 48)	P value*
Demographics, mean (SD) or n (%)
Sex, male	58 (66.7)	22 (56.4)	36 (75)	0.11
Race, Caucasian	58/78 (74.3)	29/31 (93.5)	29/47 (61.7)	0.001
Age at symptom onset in years	11.6 (2.6)	12.3 (2.6)	10.9 (2.5)	0.01
Age at diagnosis in years	13 (2.8)	14.3 (2.7)	11.9 (2.5)	< 0.001
FHx of HLA-B27-associated disease (FDR)	7 (8)	2 (5.1)	5 (10.4)	0.45
Clinical characteristics, n (%)
Back pain	40 (46)	23 (59)	17 (35.4)	0.033
Sacroiliac tenderness	27 (31)	19 (48.7)	8 (16.7)	0.002
Positive modified Schober test	13/65 (20)	7/17 (41.2)	6 (21.5)	0.029
Positive FABER test	12/66 (18.2)	6/18 (33.3)	6 (12.5)	0.07
Enthesitis	22 (25.3)	3 (7.7)	19 (39.6)	0.001
Peripheral arthritis	61 (70.1)	17 (43.6)	44 (91.7)	< 0.001
Arthritis in a male over 6 years old	58 (66.7)	22 (56.4)	36 (75)	0.11
Acute symptomatic uveitis	3 (3.4)	0 (0)	3 (6.2)	0.25
HLA-B27 positivity	40/70 (54.8)	8/25 (32)	32 (66.7)	0.007
ANA- positive	19/73 (26)	10/28 (35.7)	9/45 (20)	0.17
CRP, elevated	36/74 (48.6)	17/30 (56.7)	19/44 (43.2)	0.34
ESR, elevated	30/62 (48.4)	9/17 (52.9)	21/45 (46.7)	0.78
MRI defined Sacroiliitis	40/67 (59.7)	29/30 (96.7)	11/37 (29.7)	< 0.001
Treatment before or at time of diagnosis, n (%)
NSAIDs	72 (82.8)	27 (69.2)	45 (93.7)	0.004
DMARDs (sulfasalazine or methotrexate)	12 (13.8)	8 (20.5)	4 (8.3)	0.13
Biologics	7 (8)	3 (7.7)	4 (8.3)	1

*P-value of < 0.05 is considered statistically significant. SD Standard deviation, IL Israel, FHx family history, HLA Human leukocyte antigen, FDR first degree relative, FABER Flexion Abduction External Rotation, ANA Antinuclear antibody, CRP C-reactive protein, ESR Erythrocyte sedimentation rate, MRI Magnetic resonance imaging