| Birth cohort | Average projected admission rate as a ratio of the 1970–1974 cohort rate (95% CI) | |||||||
|---|---|---|---|---|---|---|---|---|
| End of study period (2010/11) | 1-yr projection (2011/12) | 5-yr projection (2011/12–2015/16) | 2015/16 | 10-yr projection (2011/12–2020/21) | 2020/21 | Same-age† | Until age 90 (from 2011/12) | |
| 1915–1919 | 2.9 (1.4–6.1) | 2.7 (0.9–4.5) | – | – | – | – | – | – |
| 1920–1924 | 2.4 (1.4–4.1) | 2.1 (1.5–2.8) | 1.6 (0.5–2.7) | 1.2 (0–2.3) | – | – | – | – |
| 1925–1929 | 4.4 (3.0–6.4) | 3.7 (2.3–5.2) | 2.4 (1.3–3.6) | 1.6 (0.6–2.7) | 1.6 (0.5–2.6) | 0.8 (0–2.1) | – | – |
| 1930–1934 | 7.0 (5.0–9.7) | 6.1 (3.8–8.3) | 3.5 (2.0–5.0) | 2.2 (1.0–3.4) | 2.0 (1.0–3.0) | 0.8 (0.2–1.4) | – | 0.2 (0.1–0.3) |
| 1935–1939 | 4.7 (3.4–6.6) | 5.8 (3.4–8.2) | 4.1 (2.6–5.7) | 3.1 (1.8–4.5) | 2.6 (1.5–3.7) | 1.1 (0.4–1.8) | 0.8 (0.4–1.2) | 0.3 (0.1–0.4) |
| 1940–1944 | 6.3 (4.6–8.6) | 6.0 (4.3–7.8) | 4.7 (3.0–6.4) | 3.9 (2.3–5.6) | 3.5 (2.1–5.0) | 2.3 (1.1–3.4) | 1.0 (0.5–1.5) | 0.5 (0.2–0.7) |
| 1945–1949 | 8.8 (6.5–11.8) | 9.3 (6.2–12.4) | 6.9 (4.5–9.4) | 5.7 (3.5–8.0) | 5.3 (3.2–7.4) | 3.8 (2.0–5.6) | 1.6 (0.9–2.3) | 0.9 (0.5–1.4) |
| 1950–1954 | 17.6 (13.2–23.5) | 17.8 (10.9–24.7) | 14.0 (9.3–18.6) | 11.7 (7.3–16.0) | 10.7 (6.7–14.7) | 7.5 (4.0–10.9) | 3.6 (2.3–4.9) | 2.4 (1.5–3.4) |
| 1955–1959 | 13.7 (10.3–18.2) | 13.9 (9.7–18.1) | 11.5 (7.7–15.3) | 10.0 (6.3–13.6) | 9.1 (5.8–12.4) | 6.6 (3.7–9.4) | 3.4 (2.1–4.7) | 2.6 (1.6–3.6) |
| 1960–1964 | 5.6 (4.2–7.6) | 6.2 (4.5–7.9) | 5.6 (3.7–7.5) | 5.2 (3.2–7.1) | 4.8 (3.0–6.6) | 3.8 (2.2–5.5) | 2.2 (1.4–3.1) | 1.9 (1.2–2.6) |
| 1965–1969 | 3.4 (2.5–4.7) | 3.7 (2.5–5.0) | 3.4 (2.2–4.6) | 3.3 (2.1–4.6) | 3.2 (2.0–4.4) | 3.0 (1.8–4.1) | 2.1 (1.3–2.8) | 1.9 (1.2–2.6) |
| 1970–1974* | – | – | – | – | – | – | – | – |
| 1975–1979 | 0.7 (0.4–1.0) | 0.7 (0.4–1.0) | 0.6 (0.3–1.0) | 0.6 (0.2–1.0) | 0.6 (0.2–1.0) | 0.6 (0.2–1.1) | 1.1 (0.4–1.8) | 1.1 (0.4–1.8) |
| 1980–1984 | 0.1 (0.1–0.3) | 0.1 (0–0.3) | 0.3 (0–0.6) | 0.3 (0–0.8) | 0.3 (0–0.7) | 0.3 (0–0.8) | 0.7 (0–1.5) | 1.0 (0–2.5) |
Note: CI = confidence interval. *The number of annual hospital admissions was too small to use either the oldest or youngest birth cohort as a reference. The 1970–1974 birth cohort was selected to be the reference group and to allow comparison of prevalence ratios with the same age group used in the development of the US Centers for Disease Control and Prevention guidelines. †Same-age rate ratios were calculated at age 75.