Results of receiver-operator characteristic (ROC) analysis for cutoff value for the definition of a positive result
| Cutoff Value (%) | Sensitivity (%) | Specificity (%) | Accuracy (%) | Positive Predictive Value (%) | Negative Predictive Value (%) |
|---|---|---|---|---|---|
| ≥0 | 100 | 0 | 45 | 45 | - |
| ≥10 | 91 | 21 | 52 | 48 | 75 |
| ≥20 | 89 | 26 | 54 | 49 | 75 |
| ≥30 | 79 | 40 | 57 | 51 | 70 |
| ≥40 | 72 | 50 | 60 | 54 | 69 |
| ≥50 | 70 | 74 | 72 | 69 | 75 |
| ≥60 | 60 | 78 | 70 | 68 | 70 |
| ≥70 | 57 | 86 | 73 | 77 | 71 |
| ≥80 | 36 | 90 | 66 | 74 | 63 |
| ≥90 | 21 | 91 | 60 | 67 | 59 |
| =100 | 4 | 100 | 57 | 100 | 56 |
Note:—Cutoff value indicates the cutoff value of percent decrease in radiating pain compared with the pre-injection state.