Table 5

The sensitivity and specificity of the EULAR and ACR classification criteria sets for hand OA

Sensitivity*Specificity*†
HOSTAS
  • ACR criteria for hand OA ‡

0.69 (300/433)
  • EULAR criteria for overall hand OA

0.57 (246/433)
  • EULAR criteria for interphalangeal OA and/or thumb base OA

0.66 (287/433)
MUST
  • ACR criteria for hand OA ‡

0.71 (193/270)0.63 (211/333)
  • EULAR criteria for overall hand OA

0.70 (189/270)0.63 (209/333)
  • EULAR criteria for interphalangeal OA and/or thumb base OA

0.73 (196/270)0.60 (201/333)
Phase 1 data set
  • ACR criteria for hand OA ‡

0.63 (66/105)0.80 (51/64)
  • EULAR criteria for overall hand OA

0.74 (78/105)0.78 (50/64)
  • EULAR criteria for interphalangeal OA and/or thumb base OA

0.78 (82/105)0.77 (49/64)
  • *The sensitivity and specificity were tested in participants with available information about both criteria sets. People with previous surgery of thumb base joint were excluded from analyses since missing information about bony enlargement, deformity and radiographic findings in the thumb base joints would affect the ability to apply the criteria, and in particular the EULAR criteria for thumb base OA.

  • †When people with psoriasis (n=28 in HOSTAS, n=56 in MUST and n=15 in phase 1 data set) were classified as non-hand OA cases, the specificity of the EULAR criteria for overall hand OA increased from 0.63 to 0.67 in MUST and 0.78 to 0.83 in the phase 1 data set, while the sensitivity decreased from 0.57 to 0.54 in HOSTAS, 0.70 to 0.60 in MUST and 0.74 to 0.67 in the phase 1 data set.

  • ‡Using the traditional format of the clinical ACR criteria, as described by Altman in 1990.7 In comparison with the ACR clinical criteria, sensitivity analyses of ACR radiographic criteria demonstrated lower sensitivity (0.64) in HOSTAS, similar sensitivity (0.72) and specificity (0.62) in MUST, and higher sensitivity (0.69) and specificity (0.83) in the phase 1 data set.

  • ACR, American College of Rheumatology; EULAR, European Alliance of Associations for Rheumatology; HOSTAS, Hand OA in Secondary Care Study; MUST, Musculoskeletal pain in Ullensaker STudy; OA, osteoarthritis.