Table 4

External validation of the subtype-specific GRSs in CLARITY and CHOP. Based on logistic regression on the test sets, optionally adjusted for sex and top 10 genetic principal components. Effect sizes are per SD of the GRS

	AUC (95% CI)		OR (95% CI)
	CHOP	CLARITY	CHOP	CLARITY
Enthesitis-related
GRS	0.70 (0.63 to 0.77)	0.84 (0.71 to 0.97)	1.84 (1.60 to 2.17)	2.99 (2.11 to 4.54)
GRS+sex+PCs	0.75 (0.68 to 0.82)	0.93 (0.86 0.99)	1.86 (1.61 to 2.14)	3.09 (2.07 to 5.04)
Oligoarthritis
GRS	0.77 (0.73 to 0.80)	0.74 (0.70 to 0.79)	1.93 (1.76 to 2.11)	2.24 (1.88 to 2.71)
GRS+sex+PCs	0.80 (0.77 to 0.84)	0.79 (0.76 to 0.83)	1.93 (1.75 to 2.13)	2.19 (1.81 to 2.71)
RF-negative
GRS	0.64 (0.59 to 0.69)	0.66 (0.59 to 0.73)	1.48 (1.33 to 1.64)	1.69 (1.42 to 2.02)
GRS+sex+PCs	0.76 (0.72 to 0.80)	0.74 (0.68 to 0.80)	1.51 (1.35 to 1.68)	1.71 (1.42 to 2.07)
RF-positive
GRS	0.57 (0.47 to 0.67)	0.59 (0.40 to 0.78)	0.73 (0.44 to 1.11)	1.42 (0.85 to 2.17)
GRS+sex+PCs	0.79 (0.73 to 0.86)	0.97 (0.94 to 0.99)	0.74 (0.44 to 1.13)	1.27 (0.60 to 2.52)
Psoriatic
GRS	0.56 (0.47 to 0.65)	0.58 (0.44 to 0.73)	0.77 (0.52 to 1.08)	1.33 (0.87 to 1.91)
GRS+sex+PCs	0.70 (0.62 to 0.78)	0.76 (0.66 to 0.85)	0.77 (0.52 to 1.08)	1.32 (0.85 to 1.96)
Undifferentiated
GRS	0.48 (0.35 to 0.61)	0.52 (0.42 to 0.62)	0.89 (0.60 to 1.31)	0.89 (0.59 to 1.31)
GRS+sex+PCs	0.69 (0.58 to 0.80)	0.75 (0.66 to 0.83)	0.90 (0.60 to 1.33)	0.82 (0.51 to 1.28)
Systemic
GRS	0.50 (0.43 to 0.58)	0.52 (0.41 to 0.62)	1.01 (0.78 to 1.30)	1.07 (0.73 to 1.56)
GRS+sex+PCs	0.69 (0.62 to 0.76)	0.75 (0.66 to 0.84)	1.01 (0.78 to 1.30)	1.13 (0.73 to 1.72)

AUC, area under the receiver operating characteristic curve; CHOP, Children’s Hospital of Philadelphia; CLARITY, ChiLdhood Arthritis Risk factor Identification sTudY; GRS, genomic risk score; PCs, principal components.