Table 1. Subarachnoid Hemorrhage (SAH) Incidence, Risk Ratios (RRs), Midyear Range, and Time Trends by Region.
| Geographic Location | No. of Study Periods | Overall SAH Incidence (95% CI) | I2, % | RR of Overall Incidence (95% CI) | Time Trends | |||
|---|---|---|---|---|---|---|---|---|
| Range of Midyears | SAH Incidence (95% CI) | Annual Change, % (95% CI) | ||||||
| 1980 | 2010 | |||||||
| Global | 84 | 7.9 (6.9 to 9.0) | 96.6 | NA | 1955-2014 | 10.2 (8.4 to 12.5) | 6.1 (4.9 to 7.5) | −1.7 (−2.8 to −0.6) |
| Europe overall | 45 | 8.3 (7.2 to 9.5) | 91.7 | 1 [Reference] | 1972-2010 | 10.6 (8.5 to 13.3) | 6.3 (4.9 to 8.1) | −1.7 (−3.1 to −0.4) |
| Europe without Finland | 40 | 7.5 (6.6 to 8.6) | 87.6 | 1 [Reference]a | 1972-2010 | 8.4 (6.4 to 11.1) | 6.9 (5.4 to 8.8) | −0.7 (−2.2 to 0.8) |
| Finland | 5 | 16.6 (13.4 to 20.5)b | 65.8 | 2.1 (1.5 to 3.1)a | 1972-1990 | 16.6 (13.4 to 20.6) | ND | −0.1 (−3.5 to 3.5) |
| Asia overall | 13 | 10.4 (5.9 to 18.6) | 99.5 | 1.4 (1.0 to 1.9) | 1977-2010 | 14.3 (4.9 to 41.5) | 7.7 (2.8 to 21.7) | −2.0 (−7.9 to 3.9) |
| Asia without Japan | 6 | 4.3 (0.5 to 36.4) | 95.5 | 0.6 (0.4 to 0.9) | 1984-2010 | 5.5 (0.9 to 32.2) | 3.7 (0.1 to 13.3) | −1.3 (−9.8 to 7.2) |
| Japan | 7 | 22.5 (20.3 to 24.9) | 78.5 | 2.6 (1.8 to 3.9) | 1977-2006 | 17.6 (15.4 to 20.1) | 28.0 (25.3 to 31.0) | 1.6 (0.8 to 2.3) |
| Australia/New Zealand | 10 | 8.5 (7.8 to 9.3) | 0 | 0.9 (0.7 to 0.9) | 1982-2010 | 9.4 (0.8 to 11.0) | 7.4 (6.0 to 9.2) | −0.8 (−1.8 to 0.3) |
| North America | 7 | 8.5 (7.1 to 10.2) | 68.9 | 0.7 (0.6 to 0.8) | 1955-2008 | 8.0 (7.2 to 10.1) | 6.9 (4.8 to 10.0) | −0.7 (−1.8 to 0.4) |
| South/Middle America | 8 | 4.8 (4.1 to 5.6) | 7.4 | 0.5 (0.4 to 0.8) | 1998-2014 | 3.3 (1.6 to 7.1) | 5.1 (4.2 to 6.1) | 1.4 (−1.5 to 4.3) |
| Africa | 1 | 4.1 (2.6 to 6.3) | NA | 0.5 (0.2 to 1.5) | 2011 | NA | NA | NA |
Abbreviations: NA, not applicable; ND, no data.
a
Europe without Finland; the RR for Finland is in comparison with this reference. For the remainder of the comparison, Europe as a whole including Finland is used as the reference value.
b
The overall Finnish SAH incidence is derived from incidence studies with a midyear range from 1972 to 1990.