Table 1.
Basic characteristics of the two viscosity groups.
| Demographic | RV (n=58) | LV (n=60) | p value∗ |
|---|---|---|---|
| Age (year, mean ± SD) | 55.2 ± 13.7 | 54.9 ± 15.9 | 0.931 |
| Weight (kg, mean ± SD) | 58.2 ± 7.3 | 59.2 ± 4.8 | 0.381 |
| Height (cm, mean ± SD) | 162.6 ± 6.6 | 163.5 ± 3.4 | 0.352 |
| Sex (number, male:female) | 38 : 20 | 41 : 19 | 0.745 |
| History of smoking (%) | 25.9 | 33.3 | 0.374 |
| Diagnosis (number, herniation : stenosis : both) | 38 : 17 : 3 | 38 : 19 : 3 | 0.962 |
| Level of injection (number, L4 : L5) | 12 : 46 | 14 : 46 | 0.729 |
RV: group of raw viscosity; LV: group of low viscosity; SD: standard deviation. ∗A statistically significant difference in the basic characteristics of the two groups is analyzed by the independent Student's t-test or Pearson's chi-squared test.