Table 2

The 2023 EULAR classification criteria set for interphalangeal OA

Score
Target population (mandatory criteria): persons with pain, aching and/or stiffness in at least one target joint (bilateral second–fifth DIPs, second–fifth PIPs and IP1 joints) on most days of the previous 6 weeks, and no other disease or acute injury that can explain the symptoms.*
Classification criteria for interphalangeal OA (score-based algorithm: the scores of the five criteria A–E should be added, and a score of ≥8/15 is needed for classification of interphalangeal OA):
Age
 Below 45 years0
 45–54 years1
 55–64 years2
 65 years and above3
Duration of morning stiffness in DIPs, PIPs and IP1 joints
 Long (more than 30 min)0
 None1
 Short (30 min or less)2
Number of DIPs, PIPs and IP1 joints with osteophytes
 None0
 1–2 joint(s)2
 3–5 joints3
 6 or more joints4
Number of DIPs, PIPs and IP1 joints with JSN
 None0
 1–2 joint(s)1
 3–52
 6 or more joints3
Symptom-structure concordance †
 No0
 Yes3
  • *Differential diagnoses may include crystal arthropathies, non-inflammatory hand conditions such as haemochromatosis and systemic inflammatory joint diseases such as rheumatoid arthritis and psoriatic arthritis. People with a history of psoriasis should be excluded from the target population.

  • †Radiographic OA (osteophytes or JSN) in at least 50% of the joints (DIPs, PIPs and IP1), in which the person has experienced pain, aching and/or stiffness on most days of the previous 6 weeks.

  • DIPs, distal interphalangeal joints; EULAR, European Alliance of Associations for Rheumatology; IP1, first interphalangeal; JSN, joint space narrowing; OA, osteoarthritis; PIPs, proximal interphalangeal joints.