Table 3

Clinical characteristics of patients with clinically suspect arthralgia without and with subclinical inflammation on MRI

Subclinical MRI-inflammation* present (n=41)Subclinical MRI-inflammation* absent (n=52)p-value†
Women, %29 (70.7)39 (75.0)0.64
Age in years, mean (SD)50.4 (13.7)37.9 (11.1)<0.001
Family history of RA, n (%)12 (29.3)18 (34.6)0.58
Symptom duration
 In weeks, median (IQR)14.8 (8.4–30.9)14.6 (8.9–26.4)0.90
 ≤12 weeks, n (%)17/40 (42.5)17/49 (34.7)0.45
Symptom onset0.12
 Gradual, n (%)29 (70.7)43/51 (84.3)
 Subacute, n (%)12 (29.3)8/51 (15.7)
Localisation of initial symptoms‡
 Small joints, n (%)31 (75.6)45 (86.5)Embedded Image0.12
 Large joints, n (%)2 (4.9)4 (7.7)
 Both, n (%)8 (19.5)3 (5.8)
Localisation of initial symptoms‡
 Upper extremities, n (%)28 (68.3)37 (71.2)Embedded Image0.15
 Lower extremities, n (%)6 (14.6)2 (3.8)
 Both, n (%)7 (17.1)13 (25.0)
Symmetrical localization of initial symptoms‡, n (%)28 (68.3)36/51 (71.4)0.81
Presence of inflammatory character joint pain§¶, n (%)29 (70.7)41 (78.8)0.37
Presence of morning stiffness§
 In minutes, median (IQR)60 (15–90)45 (15–90)0.34
 ≥60 minutes, n (%)21 (51.2)18 (34.6)0.11
BMI, median (IQR) in kg/m225.7 (23.1–30.3)24.5 (21.8–27.8)0.089
68-TJC, median (IQR)4 (2.5–9.0)6 (3–14.3)0.10
Current smoker, n (%)8 (19.5)11 (21.2)0.85
Current alcohol user**, n (%)27/40 (67.5)33/50 (66.0)0.88
ACPA-positivity, n (%)9 (22.0)4 (7.7)0.049
IgM-RF-positivity, n (%)12 (29.3)10 (19.2)0.26
Increased CRP (>10 mg/L), n (%)7 (17.1)4 (7.7)0.16
Increased ESR (reference for age), n (%)7 (17.1)3 (5.8)0.081
  • SD, standard deviation; n, number; IQR, interquartile range; BMI, body mass index; TJC, tender joint count; ACPA, anti-citrullinated peptide antibodies; IgM-RF, immunoglobulin-M rheumatoid factor; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate.

  • *Subclinical MRI-inflammation is defined as a combined inflammation-score (sum of synovitis-, bone marrow edema- and tenosynovitis-scores) ≥3.

  • †Calculated with the χ2, unpaired t or Mann-Whitney U tests as appropriate.

  • ‡Initial symptoms refer to the first symptoms.

  • §The presence of symptoms refers to the presence of these symptoms at the baseline visit.

  • ¶ Defined as joint pain that is worst in the early morning and improves with movement during the day.

  • **Patients not consuming daily alcohol but only one or few beverages a week were considered as alcohol users.

  • Data on symptom duration and BMI were missing in 4 patients; symptom onset and symmetrical localization in 1 patient; 68-TJC in 2 patients and alcohol use in 3 patients.