Table 4. Multivariate linear regression models to identify factors which independently associate with power Doppler scores.

	Model 1			Model 2			Model 3			Model 4			Model 5
	MS: duration			MS: severity VAS on awakening			MS: VAS improvement at first 1/4 of awake time			MS: VAS improvement at first 1/2 of awake time			MS: VAS improvement at bedtime
	SJC	TJC	MS	SJC	TJC	MS	SJC	TJC	MS	SJC	TJC	MS	SJC	TJC	MS
Intra-articular synovial power Doppler score
β	0.506	0.243	-0.039	0.469	0.240	0.069	0.465	0.250	0.083	0.453	0.247	0.119	0.446	0.244	0.126
p value	< 0.001	0.025	0.659	< 0.001	0.027	0.499	< 0.001	0.021	0.388	< 0.001	0.022	0.213	< 0.001	0.023	0.197
Tenosynovial power Doppler score
β	0.218	0.210	-0.067	0.018	0.200	0.384	0.057	0.243	0.332	0.028	0.228	0.429	0.013	0.216	0.436
p value	0.105	0.119	0.541	0.896	0.112	0.002	0.680	0.059	0.005	0.832	0.063	< 0.001	0.919	0.078	< 0.001

MS, morning stiffness; VAS, visual analogue scale; SJC, swollen joint count; TJC, tender joint count; β, standardized coefficient