Table 2 Hydrocephalus incidence rates
|  | Rate per 100,000 PMs among SMA cases (N = 5354) (IR [95% CI]) | Rate per 100,000 PMs among non-SMA matched controls (N = 5354) (IR [95% CI]) | Incidence rate ratioa (95% CI) |
|---|---|---|---|
Incident hydrocephalus events | 42 | 9 | Â |
Overall incidence rate | 15.5 (11.2–20.9) | 3.3 (1.5–6.3) | 4.7 (2.4–10.2) |
Incidence rate by sex | |||
 Female | 13.9 (8.2–21.9) | 2.3 (0.5–6.7) | 6.0 (1.9–25.7) |
 Male | 17.0 (10.9–25.3) | 4.2 (1.6–9.2) | 4.0 (1.7–10.8) |
Incidence rate by age at index date (years) | |||
 < 1 | 50.7 (6.1–183.3) | 0.00 | N/C |
 1 to < 2 | 55.5 (11.4–162.1) | 0.00 | N/C |
 2 to < 13 | 17.3 (5.6–40.4) | 3.4 (0.1–19.1) | 5.1 (0.7–120.1) |
 13 to ≤ 20 | 16.6 (3.4–48.5) | 5.5 (0.1–30.7) | 3.0 (0.3–79.3) |
 21 to ≤ 30 | 9.8 (1.2–35.5) | 0.00 | N/C |
 31 to ≤ 40 | 0.00 | 0.00 | N/C |
 41 to ≤ 50 | 2.8 (0.1–15.9) | 2.8 (0.1–15.9) | 1.0 (0.0–39.0) |
 > 50 | 21.7 (14.2–31.8) | 5.0 (1.8–10.9) | 4.4 (1.9–11.6) |