The relationship between synovitis quantified by an ultrasound 7-joint inflammation score and physical disability in rheumatoid arthritis – a cohort study

Table 4 Time-lag model

Predictor	RA	β (95% CI)	P value*	P value**	Percent variability explained - R ²
Previous DAS28-CRP	all	0.102 (0.062; 0.143)	<0.001		29.0
	i	0.072 (-0.008; 0.152)	0.079	0.353
	p	0.115 (0.069; 0.161)	<0.001
Previous GSsynSS	all	0.003 (-0.006; 0.012)	0.530		7.4
	i	0.000 (-0.019; 0.019)	1.000	0.713
	p	0.004 (-0.007; 0.015)	0.465
Previous PDsynSS	all	-0.003 (-0.015; 0.009)	0.605		0.4
	i	-0.001 (-0.021; 0.019)	0.924	0.816
	p	-0.004 (-0.018; 0.011)	0.595
Previous GStenSS	all	0.006 (-0.044; 0.056)	0.822		0.7
	i	0.005 (-0.089; 0.099)	0.922	0.972
	p	0.007 (-0.053; 0.066)	0.825
Previous PDtenSS	all	-0.005 (-0.041; 0.032)	0.801		0.5
	i	-0.019 (-0.092; 0.054)	0.606	0.655
	p	0.000 (-0.042; 0.042)	1.000
Previous ES	all	0.028 (-0.007; 0.062)	0.118		0.4
	i	-0.043 (-0.158; 0.072)	0.462	0.216
	p	0.033 (-0.004; 0.070)	0.081
Previous HAQ	all	0.740 (0.676; 0.803)	<0.001		63.5
	i	0.627 (0.496; 0.759)	<0.001	0.050
	p	0.775 (0.705; 0.846)	<0.001

Univariate analyses and interaction with incident (i) or prevalent (p) rheumatoid arthritis (RA). Predicted variable is current HAQ score, univariate predictors are previous disease activity score in 28 joints using C-reactive protein (DAS28-CRP), sum-scores for greyscale (GS) and power Doppler (PD) synovitis (syn), GS and PD tenosynovitis (ten), and erosions score (ES). *P value of significance of given β. **P value of significance of difference between incident and prevalent RA. P-values higlighted in italics are significant at p < 0.05

ISSN: 1478-6362