Page 106 - Predicting survival in patients with spinal bone metastasesL
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                                CHAPTER VII
Table 2 shows the SINS scores for each individual observer. The level of agreement between all four observers for the final SINS score was moderate (κ=0.536, p<0.001). The level of agreement was fair for the components bone lesion (κ=0.299, p<0.001) and spinal alignment (κ=0.358, p<0.001), whereas the components vertebral body collapse (κ=0.453, p<0.001) and posterolateral element involvement (κ=0.436, p<0.001) had a moderate level of agreement.
Table 2. Individual Spinal Instability Neoplastic Score and Fleiss’ kappa. *) Variables location and pain were determined separately and therefore identical among all four observers.
  SINS
    Kappa
   Observer 1 N (%)
   Observer 2 N (%)
   Observer 3 N (%)
   Observer 4 N (%)
 Bone lesion Lytic
Mixed
Blastic
Spinal alignment
Subluxation/translation Kyphosis/scoliosis Normal alignment
Vertebral body collapse >50% Collapse
<50% Collapse
None, >50% involvement None of the above
Posterolateral elements Bilateral
Unilateral
None
Location* Junctional Mobile spine Semi-rigid Rigid
Pain*
Yes; mechanical pain
Yes; non-mechanical pain No
Total SINS score
Stable (0-6 points) Uncertain (7-12 points) Unstable (13-18 points)
0.299 0.358 0.453
0.436 -
- 0.536
88 (80) 17 (16) 5 (4)
1 (1) 12 (11) 97 (88)
14 (13) 27 (24) 22 (20) 47 (43)
12 (11) 28 (25) 70 (64)
50 (55) 25 (23) 35 (32) 0 (0)
24 (22) 80 (73) 6 (5)
50 (46) 55 (50) 5 (4)
70 (64) 29 (26) 11 (10)
3 (3)
8 (7) 99 (90)
15 (14) 41 (37) 14 (13) 40 (36)
27 (25) 43 (40) 40 (36)
50 (55) 25 (23) 35 (32) 0 (0)
24 (22) 80 (73) 6 (5)
41 (37) 63 (57) 6 (6)
80 (73) 19 (17) 11 (10)
4 (4)
7 (6) 99 (90)
16 (15) 28 (25) 39 (36) 27 (24)
43 (39) 36 (33) 31 (28)
50 (55) 25 (23) 35 (32) 0 (0)
24 (22) 80 (73) 6 (5)
31 (28) 70 (64) 9 (8)
51 (46) 45 (41) 14 (13)
1 (1) 20 (18) 89 (91)
14 (13) 49 (44) 23 (21) 24 (22)
23 (21) 24 (22) 63 (57)
50 (55) 25 (23) 35 (32) 0 (0)
24 (22) 80 (73) 6 (5)
37 (34) 70 (63) 3 (3)
 Table 3 shows the sensitivity, specificity, positive predictive value and negative predictive value of the SINS for all four observers. Sensitivity ranged from 35%- 69%, specificity from 18%-48%, positive predictive value from 6%-18% and negative predictive value from 63%-90%.
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