Table 5

Radiographic and laboratory features and their association with hand OA and discriminatory capacity

OR (95% CI)AUC (95% CI)*
Number of joints with radiographic osteophytes:

  • DIP joints

1.62 (1.40–1.88)0.82 (0.76–0.88)

  • PIP joints

1.45 (1.27–1.67)0.78 (0.71–0.85)

  • MCP joints

1.22 (0.91–1.63)0.58 (0.49–0.66)

  • CMC1

2.17 (1.47–3.21)0.67 (0.59–0.75)
Number of joints with radiographic joint space narrowing:

  • DIP joints

1.57 (1.36–1.82)0.82 (0.76–0.89)

  • PIP joints

1.45 (1.24–1.69)0.77 (0.70–0.84)

  • MCP joints

0.98 (0.80–1.20)0.51 (0.42–0.60)

  • CMC1

1.94 (1.29–2.91)0.63 (0.55–0.71)
Number of joints with radiographic central erosions:

  • DIP joints

2.90 (1.67–5.04)0.72 (0.65–0.80)

  • PIP joints

1.52 (1.04–2.21)0.58 (0.50–0.67)
Number of joints with radiographic marginal erosions:

  • PIP joints

0.96 (0.57–1.63)0.53 (0.44–0.61)

  • MCP joints

0.57 (0.27–1.21)0.52 (0.43–0.61)

  • Wrist bones

0.53 (0.29–0.98)0.56 (0.47–0.65)
Laboratory tests:

  • Elevated CRP ≥5 mg/L

0.45 (0.24–0.85)0.59 (0.50–0.67)

  • Elevated ESR ≥15 mm/hour

0.39 (0.20–0.75)0.61 (0.52–0.70)

  • Positive anti-cyclic citrullinated protein

0.13 (0.04–0.50)0.62 (0.51–0.72)

  • Positive rheumatoid factor

0.35 (0.14–0.87)0.59 (0.49–0.70)

  • *Interpretation of AUC values: 0.50–0.59 = no discrimination, 0.60–0.69 = poor discrimination, 0.70–0.79 = acceptable discrimination, and ≥0.80 = excellent discrimination.

  • AUC, area under receiver operating curves; CMC1, first carpometacarpal; CRP, Creactive protein; DIP, distal interphalangeal; ESR, erythrocyte sedimentation rate; MCP; metacarpophalangeal; OA, osteoarthritis; PIP, proximal interphalangeal.