Generalised estimating equation model with ILAE grade at previous year and years since surgery (year)
| Explanatory variable | OR* |
| ILAE grade in previous year=2 | 2.50 (1.87 to 3.35) |
| ILAE grade in previous year≥3 | 138.77 (106.41 to 180.97) |
| Year | 1.00 (0.99 to 1.02) |
*OR in comparison to the category: previous ILAE grade=1.
ILAE, The International League against Epilepsy.