Diagnostic accuracy of the history (n=274)
| Characteristic | MRI+ (n=152) | MRI− (n=122) | Odds ratio (95% CI) |
|---|---|---|---|
| Values in bold indicate significant effect. | |||
| CI, confidence interval; MRI+/−, magnetic resonance imaging positive or negative. | |||
| Pain worse in leg than in back | 125 | 56 | 5.5 (3.2 to 9.4) |
| Typically dermatomal distribution | 136 | 84 | 3.8 (2.0 to 7.3) |
| Pain worse on coughing/sneezing/ straining | 76 | 40 | 2.1 (1.3 to 3.4) |
| Dermatomal cold sensations in leg | 47 | 24 | 1.8 (1.0 to 3.2) |
| More pain on sitting | 82 | 69 | 0.9 (0.6 to 1.5) |
| Less pain standing or walking | 31 | 26 | 0.9 (0.5 to 1.7) |
| Less pain on lying down | 91 | 69 | 1.1 (0.7 to 1.9) |
| Sudden onset | 60 | 51 | 0.9 (0.6 to 1.5) |
| Paroxysmal pattern | 67 | 47 | 1.3 (0.8 to 2.0) |
| Pain worse at night | 47 | 42 | 0.9 (0.5 to 1.4) |
| With known cause | 38 | 37 | 0.8 (0.5 to 1.3) |
| Subjective muscle weakness | 41 | 46 | 0.6 (0.4 to 1.0) |
| Subjective sensory loss | 60 | 51 | 0.9 (0.6 to 1.5) |
| Dermatomal paraesthesiae | 78 | 72 | 0.7 (0.5 to 1.2) |
| Previous back pain episodes | 113 | 85 | 1.3 (0.7 to 2.1) |
| Previous sciatica | 55 | 52 | 0.8 (0.5 to 1.2) |
| History indicating root compression according to investigator | 118 | 64 | 3.1 (1.9 to 5.3) |