Table 3.
Pain provoked at discography in relation to HIZ
| Provoked pain at discography | Total | ||||
|---|---|---|---|---|---|
| None | Unfamiliar | Similar | Exact | ||
| HIZ | |||||
| Absent | 18 | 17 | 22 | 18 | 75 |
| Present | 2 | 11 | 14 | 17 | 44 |
| Total | 20 | 28 | 36 | 35 | 119 |
Discography was considered reference standard and a discogram positive when pain was either exactly provoked or similarly/exactly provoked. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of HIZ in detecting painful discograms were 49 % (17/35), 69 % (57/84), 39 % (17/44) and 76 % (57/75) for exactly reproduced pain. Corresponding figures for similar/exact pain were 44 % (31/71), 73 % (35/48), 70 % (31/44) and 47 % (35/75)