Table 5

Results for outcome functional ability*

Baseline predictors (within 6 months after diagnosis)	Number of studies
Baseline predictors (within 6 months after diagnosis)	−	<†	NS	S†	>†	+	References
Demographics
Gender: female	2		5				36^, 37^, 41^, 44^, 49^, 50^, 52
Ethnicity: Hispanic	1						43
Ethnicity: Native North American				1/0			52
Higher age at onset		2/1	5				36^, 37^, 41^, 44^, 45^, 50^, 52^, 53
Higher age at diagnosis			1				49
Longer time from onset to diagnosis		2/0	2				36^, 44^, 49^, 52
Diagnosis at first visit			1				44
Family history of AS in first degree relative	1						37
Residence on a reserve	1						52
Rural residence			1				52
JIA category‡			2				44^, 50
Oligoarticular persistent
Oligoarticular extended
Systemic		1/0	3				36^, 41^, 52^, 53
Poly RF-	1	2/0	1				36^, 41^, 52^, 53
Poly RF+	1	2/0	1				36^, 41^, 52^, 53
Psoriatic			1				36
ERA			1				36
Disease activity
Higher active joint count		4/0	2				36^, 41^, 44^, 49^, 50^, 53
Higher limited joint count		0/1					36
Higher involved joint count	1		1				37^, 50
Higher articular severity score	1						53
Higher PGA		1/1	1				36^, 44^, 49
Higher parent/patient GA		2/0					36^, 49
Higher pain VAS		2/0					36^, 49
Higher CHAQ score	2						36^, 49
Higher JAQQ score	1						36
Hand involvement		2/0					41^, 53
Hip involvement	1		1				37^, 41
Ankle involvement			1				37
Symmetric involvement	2	1/0					41^, 47^, 53
Laboratory
ANA positive			2			1	50^, 52^, 53
RF positive	1	1/0	1				41^, 50^, 53
Higher ESR		2/0	4				36^, 37^, 44^, 49^, 50^, 53
Higher number of months with elevated ESR (in first 6 months)	1						41
Higher CRP			2				36^, 44
Higher number of platelets			1				44
Higher albumin level					1/0		53
Genetics
HLA-B5 (51,52)			1				53
HLA-B8			1				53
HLA-B27			1				37
HLA-B35			1				53
HLA-C3 (9,10)				1/0			53
HLA-DR1 (15,16)			1				53
HLA-DR3 (17,18)			1				53
HLA-DR5 (11,12)			1				53
HLA-DRB1*08		1/0					37
HLA-DRB1*01			1				37
HLA-DRB1*04			1				37
HLA-DPB1*02			1				37
HLA-DPB1*03			1				37
HLA-DQ3			1				53
TNF-α -308G→A			2				48^, 51
TGF-β codon 10T→C			1				48
TGF-β codon 25G→C			1				48
IFN-γ+874T→A			1				48
IL-6 -174G→C			1				48
IL-10 -1082G→A			1				48
IL-10 -819C→T			1				48
IL-10 -592C→A			1				48
MIF -173 C allele		0/1	1				54^, 55
MIF -794 CATT repeats			1				54

*Values are the number of studies that found that particular result for the respective predictors. †The first number in this column refers to the number of studies that performed a multivariate analysis disconfirming the univariate finding (studies in which the multivariate analysis confirmed the univariate finding, are shown in the columns labelled − and +, respectively). The second number in this column refers to the number of studies that did not perform a multivariate analysis. ‡In studies that evaluated onset categories oligoarticular, polyarticular and systemic, results have been duplicated for oligoarthritis persistent and extended, and polyarthritis RF-positive and RF-negative, respectively. −, lower chance of favourable outcome in multivariate analysis (p≤0.05); <, lower chance of favourable outcome in univariate analysis (p≤0.05); NS, not significant (p>0.05); S, significant in univariate analysis. Direction of the effect not shown (p≤0.05); >, higher chance of favourable outcome in univariate analysis (p≤0.05); +, higher chance of favourable outcome in multivariate analysis (p≤0.05).
ANA, antinuclear antibodies; AS, ankylosing spondylitis; CHAQ, childhood health-assessment questionnaire; CRP, C-reactive protein; ERA, enthesitis-related arthritis; ESR, erythrocyte sedimentation rate; HLA, human leucocyte antigens; IFN, interferon; IL, interleukin; JAQQ, juvenile arthritis quality of life questionnaire; JIA, Juvenile idiopathic arthritis; MIF, macrophage migratory inhibition factor; PGA, physician's global assessment; RF, rheumatoid factor; TGF, transforming growth factor; TNF, tumour necrosis factor; VAS, visual analogue scale.