TABLE 4.
Annual incidence of new diagnosis of epilepsy of structural, genetic, or unknown etiology per 100 000 population in the most deprived electoral divisions compared to the least deprived electoral divisions
| Quintile | Study population, n | Structural | Genetic | Unknown | |||
|---|---|---|---|---|---|---|---|
| n | Incidence (95% CI) | n | Incidence (95% CI) | n | Incidence (95% CI) | ||
| IR (95% CI) | IR (95% CI) | IR (95% CI) | |||||
| 1 [most deprived] | 108 753 | 47 | 43.2 (32.1–57.0) | 10 | 9.2 (4.7–16.4) | 26 | 23.9 (16.0–34.5) |
| IR = 1.73 (1.08–2.78), p = .02 | IR = 1.98 (.68–5.81), p = .20 | IR = 2.15 (1.08–4.26), p = .02 | |||||
| 2 | 108 396 | 44 | 40.6 (29.9–54) | 11 | 10.1 (5.3–17.6) | 27 | 24.9 (16.8–35.7) |
| IR = 1.62 (1.00–2.62), p = .04 | IR = 2.19 (.76–6.30), p = .14 | IR = 2.24 (1.13–4.42), p = .02 | |||||
| 3 | 108 604 | 26 | 23.9 (16–34.6) | 6 | 5.5 (2.2–11.5) | 16 | 14.7 (8.7–23.4) |
| IR = .96 (.55–1.64), p = .87 | IR = 1.19 (.36–3.90), p = .77 | IR = 1.32 (.63–2.80), p = .46 | |||||
| 4 | 109 171 | 31 | 28.4 (19.6–39.8) | 7 | 6.4 (2.8–12.7) | 20 | 18.3 (11.5–27.8) |
| IR = 1.13 (.68–1.90), p = .63 | IR = 1.38 (.44–4.36), p = .58 | IR = 1.64 (.81–3.37), p = .17 | |||||
| 5 [least deprived] | 107 944 | 27 | 25.0 (16.8–35.9) | 5 | 4.6 (1.7–10.3) | 12 | 11.1 (6.0–19.2) |
| Reference | Reference | Reference | |||||
| p for trend | p = .0038 | p = .12 | p = .02 | ||||
Note: Due to very small numbers, those with an infectious etiology and or other etiology were not analyzed (n = 4 and n = 7 across all quintiles). Trend was calculated by logistic regression of median Relative Deprivation Index for cases and noncases in each quintile.
Abbreviations: CI, confidence interval; IR, incidence ratio.