Number of patients with progression defined by newly formed or growth of syndesmophytes† (n=50)
Reader 1Reader 2Consensus‡
NewCR, n (%)CT, n (%)CR, n (%)CT, n (%)CR, n (%)CT, n (%)
 ≥127 (54)43 (86)30 (60)44 (88)19 (38)21 (42)
 ≥214 (28)38 (76)14 (28)41 (82)7 (14)15 (30)
 ≥36 (12)32 (64)8 (16)30 (60)2 (4)10 (20)
Growth
 ≥110 (20)35 (70)7 (14)32 (64)3 (6)16 (32)
 ≥28 (16)36 (52)6 (12)27 (54)3 (6)11 (22)
 ≥32 (4)23 (46)4 (8)18 (36)1 (2)6 (12)
New or growth
 ≥128 (56)45 (90)33 (66)48 (96)21 (42)25 (50)
 ≥218 (36)42 (82)19 (38)44 (88)9 (18)20 (40)
 ≥312 (24)36 (72)12 (24)38 (76)3 (6)15 (30)
  • *In the comparison of progression according to the mSASSS and CTSS, any progression is defined as progression above 0. SDC for CR was 3.8, and for CT 14.6.

  • †In the comparison of progression according to syndesmophytes, a comparison of the number of patients with ≥1, ≥2 and ≥3 newly formed syndesmophytes and syndesmophytes that grew, as well as for the combination of new formation or growth, is given.

  • ‡Both readers agree about the formation or growth of a syndesmophyte at the same vertebral corner/quadrant.

  • CR, conventional radiography; CTSS, CT Syndesmophyte Score; mSASSS, modified Stoke AS Spine Score; SDC, smallest detectable change.