Introduction
Materials and methods
Subjects and data collection
• RA | □ | ||
---|---|---|---|
• UA | □ | ||
• Non-RA: | "Inflammatory" | Psoriatic arthritis | □ |
Reactive/self-limiting inflammatory arthritis | □ | ||
Ankylosing spondylitis* | □ | ||
Enteropathic arthritis | □ | ||
Undifferentiated spondyloarthritis (not RA) | □ | ||
CTD | □ | ||
Crystal | □ | ||
Other | □ | ||
"Non-inflammatory" | Osteoarthritis | □ | |
Noninflammatory arthralgia/other. | □ |
MSUS protocol
Statistical analysis
Results
EA patient cohort and univariate analysis of baseline characteristics
Working diagnostic category (consulting rheumatologist's opinion). | Number (%) assigned diagnosis(total = 379) | |
---|---|---|
Inception:
|
Close of follow-up: (median 28 months)
| |
Undifferentiated arthritis | 91 (24.0) | 0 (-) |
Rheumatoid arthritis | 69 (18.2) | 102 (26.9) |
Psoriatic arthritis | 24 (6.3) | 25 (6.6) |
Enteropathic arthritis | 3 (0.8) | 4 (1.1) |
Reactive/self-limiting inflammatory arthritis | 21 (5.5) | 36 (9.5) |
Ankylosing spondylitis | 0 ( - ) | 2 (0.5) |
Undifferentiated spondyloarthritis | 7 (1.8) | 9 (2.4) |
Crystal arthritis (gout/pyrophosphate) | 17 (4.5) | 17 (4.5) |
Connective tissue disease | 5 (1.3) | 7 (1.8) |
Other inflammatory arthropathy | 7 (1.8) | 9 (2.4) |
Osteoarthritis | 66 (17.4) | 78 (20.6) |
Other non-inflammatory/arthralgia | 69 (18.2) | 90 (23.6) |
Clinical/Laboratory Parameters: | Overall cohort (n= 379) | Outcome diagnostic category | |||
---|---|---|---|---|---|
Non-PIA (
n
= 217);
|
PIA (
n
= 162);
|
P
-value†
| |||
Age (years) | |||||
-cat; >50 (%) | 51 | 49 | 51 | 0.533 | |
-cont; mean (SD) | 50.9 (36 to 66.) | 48.5 (34.5 to 62.5) | 53.8 (37.8 to 69.8) | 0.057 | |
Sex; F (%) | 69 | 71 | 67 | 0.540 | |
Ever smoked? (%) | 54.1 | 100, 117 | 74, 88 | 0.999 | |
Sx durn (weeks) | |||||
-cat; ≥20 (%) | 51 | 61 | 38 | <0.001 | |
-cont; median (IQR) | 20 (10 to 34) | 24 (12 to 52) | 12 (8 to 24) | <0.001 | |
TJC /72 | |||||
-cat; >6 (%) | 51 | 48 | 54 | 0.299 | |
-cont; median (IQR) | 7 (2 to 14) | 6 (2 to 14) | 7.5 (3 to 15) | 0.052 | |
SJC /72 | |||||
-cat; ≥1 (%) | 46 | 26 | 73 | <0.001 | |
-cont; median (IQR) | 0 (0 to 3) | 0 (0 to 1) | 2 (0 to 6) | <0.001 | |
JPS
| |||||
-cat; ≥2 (%) | 66 | 56 | 78 | <0.001 | |
-cont; median (IQR) | 2 (1.5 to 2) | 2 (1.5 to 2) | 2 (2 to 2.5) | <0.001 | |
EMS (hours) | |||||
-cat; ≥1 (%) | 50 | 39 | 65 | <0.001 | |
-cont; median (IQR) | 1 (0.2 to 2) | 0.5 (0.05 to 1.5) | 1 (0.5 to 2) | <0.001 | |
CRP (g/l) | |||||
-cat; <5,5 to 14,≥14 (%) | 49,26,25 | 66, 23, 11 | 25, 30, 45 | <0.001 | |
-cont; median (IQR) | 5 (<5 to 14) | <5 (<5 to 8) | 11 (<5 to 32) | <0.001 | |
ESR (mm/hr) | |||||
-cat; >24 (%) | 50 | 33 | 72 | <0.001 | |
-cont; median (IQR) | 24 (13 to 50) | 18 (9 to 13) | 45 (24 to 67) | <0.001 | |
RF; Pos (%) | Neg, Pos | 193, 24 | 97, 65 | <0.001 | |
ACPA; Pos (%) | Neg, Pos | 216, 1 | 107, 55 | <0.001 | |
MSUS Parameters
Domain/Parameter
Definition
| |||||
Grey-sale synovotis
|
∑ semi-quant. score/16 joints:
≥2 (%) | 35.1 | 19.4 | 56.2 | <0.001 |
∑ semi-quant score/6 joints (worst hand): ≥2 (%) | 29.6 | 15 | 48.8 | <0.001 | |
Number of joints/16 scoring ≥1:
≥3 (%) | 30.1 | 14.7 | 50.6 | <0.001 | |
Power Doppler synovitis
|
∑ semi-quant. Score/16 joints:
≥1 (%) | 29 | 15.7 | 46.9 | <0.001 |
Number of joints/16 scoring ≥1:
≥2 (%) | 16.9 | 7.4 | 29.6 | <0.001 |
Predictive algorithm for PIA: no MSUS
Variable | Coding if categorical | B | SE | Wald | P-value | OR (95% CI) | |
---|---|---|---|---|---|---|---|
Age
(years) | <50: | 0 | |||||
≥50: | 1 |
-0.80
| 0.32 | 6.27 |
0.012
| 0.45 (0.24 to 0.84 | |
Sx Durn
(weeks) | n/a |
-0.030
| 0.01 | 12.64 |
<0.001
| 0.97 (0.96 to 0.99) | |
SJC /72 | <1: | 0 | |||||
≥1: | 1 |
1.53
| 0.31 | 23.94 |
<0.001
| 4.61 (2.50 to 8.43) | |
JPS
| n/a |
0.42
| 0.26 | 2.66 |
0.100
| 1.52 (0.92 to 2.52) | |
CRP
(g/l) | <5: | 0 | |||||
5 to 14: | 1 |
0.77
| 0.21 | 13.48 |
<0.001
| 2.16 (1.43 to 3.27) | |
≥14: | 2 | ||||||
ESR
(mm/h) | <24 | 0 | |||||
≥24 | 1 |
0.79
| 0.34 | 5.33 |
0.021
| 2.21 (1.13 to 4.32) | |
ACPA
| Neg: | 0 | |||||
Pos: | 1 |
4.89
| 1.10 | 21.36 |
<0.001
| 132.4 (17 to 1052) | |
Constant
|
-2.12
| 0.52 | 16.63 |
<0.001
| - |
Predictive algorithm for PIA is not improved by incorporation of MSUS parameter(s)
Variable | Coding if categorical | B | SE | Wald | P-value | OR (95% CI) | |
---|---|---|---|---|---|---|---|
Age
(years) | <50: | 0 | |||||
≥50: | 1 |
-1.24
| 0.36 | 11.81 |
0.001
| 0.29 (0.14 to 0.59) | |
Sx Durn
(weeks) | n/a |
-0.03
| 0.01 | 11.182 |
0.001
| 0.97 (0.96 to 0.99) | |
SJC /72 | <1: | 0 | |||||
≥1: | 1 |
1.42
| 0.32 | 19.21 |
<0.001
| 4.14 (2.19 to 7.80) | |
CRP
(g/l) | <5: | 0 | |||||
5 to 14: | 1 |
0.64
| 0.22 | 8.43 |
0.004
| 1.89 (1.23 to 2.92) | |
≥14: | 2 | ||||||
ACPA
| Neg: | 0 | |||||
Pos: | 1 |
4.97
| 1.07 | 21.74 |
<0.001
| 143.7(18 to 1060) | |
ESR
(mm/h) | 24: | 0 | |||||
≥24: | 1 |
1.00
| 0.36 | 7.74 |
0.005
| 2.72 (1.34 to 5.51) | |
Presence of
Grade I
grey-scale synovitis in ≥3/16 joints
| No: | 0 | |||||
Yes: | 1 |
1.6
| 0.34 | 17.22 |
<0.001
| 4.91 (2.32 to 10.4) | |
Constant
|
-1.62
| 0.34 | 22.68 |
<0.001
| - |
A predictive algorithm for RA amongst the PIA sub-cohort is not improved by the incorporation of MSUS parameter(s)
Variable | Coding if categorical | B | SE | Wald | P-value | OR (95% CI) | |
---|---|---|---|---|---|---|---|
Age
(years) | <50: | 0 | |||||
≥50: | 1 |
1.52
| 0.49 | 9.52 |
0.002
| 4.58 (1.74 to 12) | |
SJC /72 | <1: | 0 | |||||
≥1: | 1 |
1.26
| 0.55 | 5.21 |
0.023
| 3.52 (1.19 to 10) | |
JPS
| n/a |
1.38
| 0.50 | 7.67 |
0.006
| 3.99(1.50 to 11) | |
ESR
(mm/h) | <24 | 0 | |||||
≥24 | 1 |
1.14
| 0.53 | 4.63 |
0.031
| 3.13 (1.11 to 8.85) | |
ACPA
| Neg: | 0 | |||||
Pos: | 1 |
4.30
| 0.88 | 24.17 |
<0.001
| 74 (13 to 409) | |
Constant
|
-5.61
| 1.26 | 20.0 |
<0.001
| - |
Variable | Coding if categorical | B | SE | Wald | P-value | OR (95% CI) | |
---|---|---|---|---|---|---|---|
Age
(years) | <50: | 0 | |||||
≥50: | 1 |
1.26
| 0.51 | 6.23 |
0.013
| 3.59 (1.32 to 9.81) | |
Presence of
GradeIP
ower Doppler synovitis in ≥1/16 joints
| No: | 0 | |||||
Yes: | 1 |
1.70
| 0.52 | 10.72 |
0.001
| 5.46 (1.98 to 15.1) | |
JPS
| n/a |
1.39
| 0.54 | 6.60 |
0.010
| 4.02(1.39 to 11.6) | |
ESR
(mm/h) | 24: | 0 | |||||
≥24: | 1 |
1.17
| 0.56 | 4.48 |
0.034
| 3.24 (1.09 to 9.60) | |
ACPA
| Neg: | 0 | |||||
Pos: | 1 |
4.06
| 0.82 | 24.74 |
<0.001
| 58.1(12 to 288) | |
Constant
|
-5.38
| 1.28 | 17.64 |
<0.001
| - |