Table 2

Reliability for change scores and sensitivity to change assessed by the smallest detectable change (SDC) and percentage of patients with progression above the SDC for the Kellgren–Lawrence grading scale (KL), OARSI atlas (OARSI) and Verbruggen–Veys anatomical phase score (VV)

KLOARSIVV
SDC (%)*Progression, N (%)SDC (%)Progression, N (%)SDC (%)Progression, N (%)
Intrareader SDC and progression above this SDC
 2-Year
  Reader 12.1 (2.8)17 (18.9)1.2 (1.1)20 (22.2)1.4 (1.2)17 (18.9)
  Reader 22.5 (2.7)22 (24.7)3.0 (2.7)16 (17.8)3.4 (2.6)9 (10.0)
  Reader 37.1 (8.9)11 (12.4)10.2 (7.3)11 (12.2)7.8 (5.2)14 (15.6)
 6-Year
  Reader 13.7 (4.7)45 (50.6)3.0 (2.5)50 (55.6)3.5 (2.6)24 (26.7)
  Reader 24.4 (4.7)51 (57.3)4.8 (3.7)54 (60.0)6.3 (4.6)19 (21.1)
  Reader 38.1 (9.3)41 (46.1)11.1 (8.0)32 (35.6)9.9 (6.1)31 (34.4)
Inter-reader SDC and progression above this SDC
 2-Year
  Reader 12.9 (3.2)17 (18.9)4.1 (2.9)6 (6.7)2.7 (1.8)12 (13.3)
  Reader 222 (24.7)11 (12.2)12 (13.3)
  Reader 350 (56.2)34 (37.8)47 (52.2)
 6-Year
  Reader 13.8 (4.1)45 (50.6)4.6 (3.3)30 (33.3)4.0 (2.5)24 (26.7)
  Reader 260 (67.4)54 (60.0)29 (32.2)
  Reader 371 (79.8)67 (74.4)59 (65.6)
  • * SDC expressed as absolute value and as percentage of maximum observed score.