Table 3.
Relationships between measurements. Pearson's correlation coefficients (r) and p-values for (a) associations between finger imaging measures in patients with SSc and visual analogue scales (VAS) and modified Rodnan skin score (mRSS) at the finger and dorsum of the hand; (b) associations between non-invasive measures at the finger (including all groups); (c) associations between non-invasive measures at the finger (including all SSc groups).
| Perfusion (distal-dorsal difference [PU]) |
Capillary density (number/mm) |
Finger oxygenation (AU) |
Finger oxidative stress (AU) |
Finger skin thickness (microns) |
|
|---|---|---|---|---|---|
| R-value (p-value, N) | |||||
| a) Pearson's correlation coefficients for finger measurements with VAS scores and mRSS (all SSc groups) | |||||
| Severity of Raynaud's VAS (0–100) | 0.02 (0.86) n = 188 |
−0.05 (0.49) n = 184 |
−0.01 (0.91) n = 133 |
−0.00 (0.96) n = 144 |
0.04 (0.58) n = 176 |
| Global disease impact VAS (0–100) |
−0.13 (0.15) n = 132 |
−0.21 (0.02)* n = 125 |
−0.10 (0.39) n = 83 |
0.08 (0.43) n = 97 |
0.08 (0.40) n = 123 |
| Impact of ulcers VAS (0–100) |
−0.06 (0.51) n = 133 |
−0.22 (0.01)* n = 126 |
−0.04 (0.69) n = 84 |
0.00 (0.97) n = 98 |
−0.05 (0.61) n = 124 |
| mRSS fingers (non-dominant finger imaged [0–3]) [30] | −0.30 (<0.001)** n = 132 |
−0.23 (0.01)* n = 125 |
−0.15 (0.16) n = 140 |
0.02 (0.84) n = 98 |
0.29 (<0.05)* n = 123 |
| mRSS dorsum of the hand imaged (one hand [0–3]) | −0.25 (<0.05)* n = 133 |
−0.10 (0.25) n = 126 |
−0.08 (0.49) n = 141 |
0.06 (0.52) n = 99 |
0.26 (<0.05)* n = 124 |
| b) Pearson's correlation coefficients for associations between non-invasive measures at the finger (including all groups) | |||||
| Perfusion (distal-dorsal difference [PU]) | 0.05 (0.4) n = 236 |
0.23 (<0.001)** n = 175 |
−0.00 (0.96) n = 189 |
−0.1 (0.15) n = 219 |
|
| Capillary density (number/mm) | 0.09 (0.26) n = 171 |
−0.10 (0.19) n = 184 |
−0.26 (<0.001) ** n = 217 |
||
| Finger oxygenation (AU) | −0.13 (0.08) n = 173 |
−0.05 (0.48) n = 167 |
|||
| Finger oxidative stress (AU) | 0.11 (0.14) n = 171 |
||||
| c) Pearson's correlation for associations between non-invasive measures at the finger (all SSc groups) | |||||
| Perfusion (distal-dorsal difference [PU]) | 0.01 (0.9) n = 119 |
0.21 (0.06) n = 78 |
0.07 (0.5) n = 93 |
−0.09 (0.37) n = 114 |
|
| Capillary density (number/mm) | 0.03 (0.83) n = 72 |
0.06 (0.57) n = 86 |
−0.16 (0.1) n = 109 |
||
| Finger oxygenation (AU) | −0.09 (0.42) n = 78 |
0.1 (0.36) n = 74 |
|||
| Finger oxidative stress (AU) | −0.01 (0.94) n = 81 |
||||
*p < 0.05, **p < 0.001. In section b) P-values must be considered in the context that there are multiple analyses performed, none of which were pre-specified.