Table 2.
All-cause mortality rate per 100,000 PYs among SMA cases, matched controls, and the US general population overall, for SMA type III only, and by gender and age at first diagnostic code date
| SMA cases (N = 5179) | Matched controls (N = 51,152) | HR comparing SMA cases to controls | US mortality in 2012 [16] | |
|---|---|---|---|---|
| Rate (95% CI) | Rate (95% CI) | HR (95% CI) | Rate (95% CI) | |
| Overall | 1926 (1792–2069) | 1099 (1066–1132) | 1.76 (1.63–1.90) | 810 (809–811) |
| SMA type III onlya | 1059 (476–2358) | 603 (431–844) | 1.76 (0.74–4.20) | NA |
| Female | 1786 (1606–1987) | 970 (926–1015) | 1.85 (1.65–2.08) | 796 (795–798) |
| Male | 2061 (1870–2271) | 1223 (1175–1273) | 1.69 (1.52–1.88) | 825 (823–826) |
| Age at first diagnostic code date, years | ||||
| < 1 | 9620 (6685–13,843) | 208 (99–437) | 43.96 (19.25–100.36) | 599 (592–607) |
| 1 to < 2 | 5114 (3428–7630) | 0b | – | 41 (39–43) |
| 2 to < 13 | 640 (418–982) | 25 (12–49) | 26.0 (11.52–58.70) | 14 (14–15) |
| 13 to ≤ 20 | 599 (355–1011) | 51 (29–91) | 11.66 (5.39–25.20) | 44 (43–44) |
| 21 to ≤ 30 | 724 (467–1123) | 105 (73–151) | 6.89 (3.90–12.18) | 94 (94–95) |
| 31 to ≤ 40 | 425 (287–630) | 128 (102–160) | 3.33 (2.12–5.23) | 133 (132–134) |
| 41 to ≤ 50 | 935 (701–1249) | 236 (196–283) | 3.99 (2.83–5.61) | 283 (282–285) |
| 51 to ≤ 60 | 1916 (1584–2318) | 661 (597–732) | 2.90 (2.34–3.61) | 644 (641/6–646) |
| > 60 | 3476 (3173–3808) | 2788 (2699–2881) | 1.26 (1.14–1.39) | 2338 (2334–2343) |
First diagnostic code date in patients with SMA was defined as the date of the first recorded SMA code. US mortality in 2012 was taken from the CDC WONDER Online Database [16]
CI confidence interval, HR hazard ratio, NA not applicable, PY person-year, SMA spinal muscular atrophy, Type III SMA only are patients with SMA diagnostic codes for ICD-9 335.11 only (i.e., no other SMA diagnostic codes)
aN = 66 SMA type III only cases and N = 631 matched controls
bThere were no deaths among the 1040 controls aged 1 to < 2 years