Table 3.

Early determinants for differentiation between juvenile PsA (n = 31) and all other JIA subtypes (n =305) as well as oligoarticular or polyarticular JIA (n = 205).

Variables Assessed at Disease Onset	Univariate Analyses^*			Multivariate Analysis^**
Variables Assessed at Disease Onset	OR	95% CI	p	OR	95% CI	p
PsA vs all other subtypes (n = 336)
Female sex	1.67	0.70–4.01	0.249
Onset age ≥ 6 yrs	1.97	0.85–4.55	0.112
Psoriasis in first-degree relative	26.35	10.84–64.07	< 0.001	30.86	10.68–89.14	< 0.001
Psoriasis in patient	14.40	4.11–50.51	< 0.001	12.06	2.26–64.40	0.004
DRB1^*11/12	2.43	1.05–5.61	0.038	3.09	0.86–9.90	0.085
Dactylitis	9.90	3.93–24.95	< 0.001	10.97	2.96–40.62	< 0.001
Small-joint arthritis	2.06	0.98–4.33	0.050
Toe arthritis	2.17	0.97–4.85	0.061
Ankle arthritis	1.99	0.94–4.22	0.071
Toe and/or ankle involvement	2.73	1.22–6.13	0.015	3.04	1.07–8.64	0.038
Finger arthritis	2.03	0.95–4.33	0.067
PsA vs oligo–/polyarthritis (n = 236)^***
Female sex	1.08	0.44–2.65	0.872
Onset age ≥ 6 yrs	2.63	1.13–6.16	0.026	4.41	1.61–12.12	0.004
DRB1^*11/12	2.13	0.90–5.04	0.085	2.69	1.05–6.91	0.040
Dactylitis	3.40	3.19–22.10	< 0.001	14.93	4.79–47.54	< 0.001
Ankle arthritis	1.92	0.89–4.12	0.096
Toe arthritis	2.09	0.91–4.80	0.082
Toe and/or ankle involvement	2.62	1.15–5.96	0.022
Hip involvement	3.39	1.09–10.54	0.035

↵* DRB1*01, DRB1*04, DPB1*02, DPB1*03, wrist or knee arthritis, nail pitting, ANA, persistently elevated ESR, and cumulative numbers of affected joints within the first 6 months of disease were not associated with diagnosis of PsA in univariate analyses (p ≥ 0.10, data not shown).
↵** Results of multiple logistic regression analysis identifying determinants of diagnosis of PsA. Variables associated with PsA in univariate analyses (p < 0.10) were included.
↵*** Psoriasis in patient or relative is an exclusion criterion from oligoarthritis and polyarthritis and could not be analyzed as an independent variable in the analyses of factors that differentiated PsA from either oligoarthritis or polyarthritis.