ACPA−RA (n=29) | ACPA+RA (n=25) | Non-RA inflam. (n=59) | OA/non-inflam. (n=71) | UA (n=3) | p Value (inflam. diagnoses*) | p Value (all diagnoses†) | |
---|---|---|---|---|---|---|---|
Age (years) | 61 (30 to 88) | 58 (27 to 81) | 51 (18 to 91) | 51 (27 to 86) | 45 (24 to 68) | 0.01 | <0.01 |
Female, % | 69 | 64 | 66 | 72 | 67 | ns | ns |
Symptom duration (weeks) | 12 (4 to >52) | 16 (4 to >52) | 9 (2 to >52) | 18 (3 to >52) | 24 (6 to 38) | ns | ns |
ESR (seconds) | 23 (1 to 71) | 21 (4 to 86) | 15 (1 to 113) | 8 (1 to 100) | 21 (20 to 29) | ns | 0.01 |
CRP (g/L) | 11 (<5 to 91) | 10 (<5 to 66) | 8 (<5 to 189) | <5 (<5 to 49) | 12 (6 to 23) | ns | 0.01 |
ACPA+, % | 0 | 100 | 4 | 0 | 9 | <0.01 | <0.01 |
RF+, % | 31 | 80 | 5 | 7 | 33 | <0.01 | <0.01 |
DAS28 | 4.8 (2.31 to 7.16) | 5.00 (1.59 to 7.07) | n/a | n/a | n/a | ns | – |
Except where indicated, median and range are given.
*Kruskal–Wallis ANOVA analysis confined to three groups with confirmed inflammatory diagnoses at inception: ACPA−RA, ACPA+RA and non-RA inflammatory arthritis.
†Kruskal–Wallis ANOVA, five groups, including OA/non-inflammatory arthralgia and UA.
ACPA, anticitrullinated peptide autoantibody; ANOVA, analysis of variance; CRP, C reactive protein DAS28, disease activity score in 28 joints; ESR, erythrocyte sedimentation rate; OA, osteoarthritis; RA, rheumatoid arthritis; RF, rheumatoid factor; UA, undifferentiated arthritis.