Table 2

Correlation between different indices and ultrasound scores

IndexFormulaGS sum scorePD sum score
PGAPGA0.35
(p<0.001)		0.39
(p<0.001)
PGA + CRPPGA + CRP0.44
(p<0.001)		0.46
(p<0.001)
ThermoJISThermoJIS0.49
(p<0.001)		0.51
(p<0.001)
ThermoDAIThermoJIS + PGA0.52
(p<0.001)		0.56
(p<0.001)
ThermoDAI-CRPThermoJIS + PGA + CRP0.58
(p<0.001)		0.61
(p<0.001)
DAS28-CRP0.56 × √TJC28+0.28 × √SJC28 + 0.014 × PGA + 0.36 × ln(CRP+1) + 0.960.62
(p<0.001)		0.63
(p<0.001)
CDAITJC28 + SJC28 + PGA + EGA0.63
(p<0.001)		0.64
(p<0.001)
SDAITJC28 + SJC28 + PGA + EGA + CRP0.65
(p<0.001)		0.65
(p<0.001)

  • CDAI, Clinical Disease Activity Index; CRP, C reactive protein; DAS28, 28-joint Disease Activity Score; GS, grey-scale synovial hypertrophy; PD, power Doppler; PGA, Patient Global Assessment; SDAI, Simplified Disease Activity Index; SJC28, swollen joints in standard 28-joints count; ThermoDAI, Thermographic Disease Activity Index; ThermoJIS, Thermographic Joint Inflammation Score; TJC28, tender joints in standard 28-joints count.