Observed versus expected incidence of type 1 diabetes (per 100,000 person-years) during year 2020 and first half of 2021, as well as during both periods with increased observed incidence
| . | Observed incidence in 2020/21 (95% CI) . | Expected incidence for 2020/21 based on data from 2011 to 2019 (95% CI) . | IRR for observed vs. expected incidence (95% CI) . | P . |
|---|---|---|---|---|
| 1 January 2020 to 30 June 2021* | ||||
| All patients | 24.4 (23.6–25.2) | 21.2 (20.5–21.9) | 1.15 (1.10–1.20) | <0.001 |
| Male patients | 26.6 (25.5–27.8) | 22.9 (21.9–24.0) | 1.16 (1.10–1.23) | <0.001 |
| Female patients | 21.9 (20.9–23.0) | 19.2 (18.2–20.2) | 1.14 (1.07–1.21) | <0.001 |
| Aged <6 years | 18.6 (17.5–19.8) | 15.1 (14.1–16.2) | 1.23 (1.13–1.33) | <0.001 |
| Aged 6–11 years | 32.7 (31.2–34.3) | 27.7 (26.3–29.2) | 1.18 (1.11–1.26) | <0.001 |
| Aged 12–17 years | 23.5 (22.2–24.8) | 22.2 (21.0–23.5) | 1.06 (0.98–1.13) | 0.13 |
| Year 2020* | ||||
| All patients | 23.7 (22.8–24.6) | 20.9 (20.0–21.8) | 1.13 (1.08–1.19) | <0.001 |
| Male patients | 25.7 (24.3–27.0) | 22.6 (21.4–23.9) | 1.13 (1.06–1.21) | <0.001 |
| Female patients | 21.5 (20.3–22.8) | 18.9 (17.7–20.1) | 1.14 (1.06–1.23) | <0.001 |
| Aged <6 years | 17.8 (16.5–19.2) | 15.2 (14.0–16.5) | 1.17 (1.06–1.30) | 0.002 |
| Aged 6–11 years | 31.4 (29.6–33.4) | 27.3 (25.6–29.1) | 1.15 (1.07–1.24) | <0.001 |
| Aged 12–17 years | 23.4 (21.8–25.1) | 21.5 (20.1–23.2) | 1.09 (1.00–1.19) | 0.06 |
| First half of year 2021* | ||||
| All patients | 25.8 (24.4–27.2) | 21.8 (20.5–23.1) | 1.18 (1.10–1.27) | <0.001 |
| Male patients | 28.6 (26.6–30.6) | 23.5 (21.7–25.4) | 1.22 (1.11–1.33) | <0.001 |
| Female patients | 22.8 (21.0–24.7) | 19.8 (18.1–21.6) | 1.15 (1.04–1.28) | 0.008 |
| Aged <6 years | 20.2 (18.2–22.4) | 15.0 (13.4–16.9) | 1.34 (1.17–1.54) | <0.001 |
| Aged 6–11 years | 35.4 (32.7–38.3) | 28.4 (26.0–31.1) | 1.24 (1.12–1.38) | <0.001 |
| Aged 12–17 years | 23.6 (21.4–26.0) | 23.6 (21.4–26.0) | 1.00 (0.89–1.13) | 0.96 |
| Period with increased incidence of type 1 diabetes in 2020 (June 2020 to September 2020)† | ||||
| All patients | 24.0 (22.0–26.1) | 18.9 (17.2–20.8) | 1.27 (1.13–1.43) | <0.001 |
| Male patients | 25.4 (22.7–28.5) | 20.6 (18.1–23.4) | 1.23 (1.05–1.44) | 0.002 |
| Female patients | 22.4 (19.8–25.4) | 16.9 (14.7–19.6) | 1.33 (1.11–1.58) | <0.001 |
| Aged <6 years | 17.8 (15.1–21.0) | 13.2 (10.8–16.0) | 1.35 (1.07–1.71) | 0.004 |
| Aged 6–11 years | 32.6 (28.7–37.1) | 25.9 (22.4–29.8) | 1.26 (1.06–1.50) | 0.003 |
| Aged 12–17 years | 23.5 (20.2–27.3) | 19.0 (16.1–22.5) | 1.23 (1.00–1.51) | 0.043 |
| Period with increased incidence of type 1 diabetes in 2021 (March 2021 to June 2021)† | ||||
| All patients | 25.5 (23.5–27.7) | 20.2 (18.4–22.1) | 1.27 (1.13–1.42) | <0.001 |
| Male patients | 28.8 (25.9–32.1) | 21.7 (19.2–24.6) | 1.33 (1.14–1.55) | <0.001 |
| Female patients | 22.1 (19.5–25.1) | 18.4 (16.0–21.1) | 1.20 (1.01–1.43) | 0.023 |
| Aged <6 years | 20.6 (17.6–24.0) | 14.1 (11.7–17.0) | 1.46 (1.17–1.83) | <0.001 |
| Aged 6–11 years | 34.0 (30.0–38.5) | 26.2 (22.8–30.2) | 1.30 (1.09–1.54) | <0.001 |
| Aged 12–17 years | 23.4 (20.2–27.2) | 21.6 (18.5–25.2) | 1.09 (0.89–1.32) | 1.00 |
| . | Observed incidence in 2020/21 (95% CI) . | Expected incidence for 2020/21 based on data from 2011 to 2019 (95% CI) . | IRR for observed vs. expected incidence (95% CI) . | P . |
|---|---|---|---|---|
| 1 January 2020 to 30 June 2021* | ||||
| All patients | 24.4 (23.6–25.2) | 21.2 (20.5–21.9) | 1.15 (1.10–1.20) | <0.001 |
| Male patients | 26.6 (25.5–27.8) | 22.9 (21.9–24.0) | 1.16 (1.10–1.23) | <0.001 |
| Female patients | 21.9 (20.9–23.0) | 19.2 (18.2–20.2) | 1.14 (1.07–1.21) | <0.001 |
| Aged <6 years | 18.6 (17.5–19.8) | 15.1 (14.1–16.2) | 1.23 (1.13–1.33) | <0.001 |
| Aged 6–11 years | 32.7 (31.2–34.3) | 27.7 (26.3–29.2) | 1.18 (1.11–1.26) | <0.001 |
| Aged 12–17 years | 23.5 (22.2–24.8) | 22.2 (21.0–23.5) | 1.06 (0.98–1.13) | 0.13 |
| Year 2020* | ||||
| All patients | 23.7 (22.8–24.6) | 20.9 (20.0–21.8) | 1.13 (1.08–1.19) | <0.001 |
| Male patients | 25.7 (24.3–27.0) | 22.6 (21.4–23.9) | 1.13 (1.06–1.21) | <0.001 |
| Female patients | 21.5 (20.3–22.8) | 18.9 (17.7–20.1) | 1.14 (1.06–1.23) | <0.001 |
| Aged <6 years | 17.8 (16.5–19.2) | 15.2 (14.0–16.5) | 1.17 (1.06–1.30) | 0.002 |
| Aged 6–11 years | 31.4 (29.6–33.4) | 27.3 (25.6–29.1) | 1.15 (1.07–1.24) | <0.001 |
| Aged 12–17 years | 23.4 (21.8–25.1) | 21.5 (20.1–23.2) | 1.09 (1.00–1.19) | 0.06 |
| First half of year 2021* | ||||
| All patients | 25.8 (24.4–27.2) | 21.8 (20.5–23.1) | 1.18 (1.10–1.27) | <0.001 |
| Male patients | 28.6 (26.6–30.6) | 23.5 (21.7–25.4) | 1.22 (1.11–1.33) | <0.001 |
| Female patients | 22.8 (21.0–24.7) | 19.8 (18.1–21.6) | 1.15 (1.04–1.28) | 0.008 |
| Aged <6 years | 20.2 (18.2–22.4) | 15.0 (13.4–16.9) | 1.34 (1.17–1.54) | <0.001 |
| Aged 6–11 years | 35.4 (32.7–38.3) | 28.4 (26.0–31.1) | 1.24 (1.12–1.38) | <0.001 |
| Aged 12–17 years | 23.6 (21.4–26.0) | 23.6 (21.4–26.0) | 1.00 (0.89–1.13) | 0.96 |
| Period with increased incidence of type 1 diabetes in 2020 (June 2020 to September 2020)† | ||||
| All patients | 24.0 (22.0–26.1) | 18.9 (17.2–20.8) | 1.27 (1.13–1.43) | <0.001 |
| Male patients | 25.4 (22.7–28.5) | 20.6 (18.1–23.4) | 1.23 (1.05–1.44) | 0.002 |
| Female patients | 22.4 (19.8–25.4) | 16.9 (14.7–19.6) | 1.33 (1.11–1.58) | <0.001 |
| Aged <6 years | 17.8 (15.1–21.0) | 13.2 (10.8–16.0) | 1.35 (1.07–1.71) | 0.004 |
| Aged 6–11 years | 32.6 (28.7–37.1) | 25.9 (22.4–29.8) | 1.26 (1.06–1.50) | 0.003 |
| Aged 12–17 years | 23.5 (20.2–27.3) | 19.0 (16.1–22.5) | 1.23 (1.00–1.51) | 0.043 |
| Period with increased incidence of type 1 diabetes in 2021 (March 2021 to June 2021)† | ||||
| All patients | 25.5 (23.5–27.7) | 20.2 (18.4–22.1) | 1.27 (1.13–1.42) | <0.001 |
| Male patients | 28.8 (25.9–32.1) | 21.7 (19.2–24.6) | 1.33 (1.14–1.55) | <0.001 |
| Female patients | 22.1 (19.5–25.1) | 18.4 (16.0–21.1) | 1.20 (1.01–1.43) | 0.023 |
| Aged <6 years | 20.6 (17.6–24.0) | 14.1 (11.7–17.0) | 1.46 (1.17–1.83) | <0.001 |
| Aged 6–11 years | 34.0 (30.0–38.5) | 26.2 (22.8–30.2) | 1.30 (1.09–1.54) | <0.001 |
| Aged 12–17 years | 23.4 (20.2–27.2) | 21.6 (18.5–25.2) | 1.09 (0.89–1.32) | 1.00 |
Using Poisson regression models, expected incidences for 2020 were estimated based on the data from 2011 to 2019 and compared with observed incidences in 2020 by estimating IRRs with 95% CIs and two-sided P values. Incidences are presented as rate per 100,000 person-years with corresponding 95% CIs. Bold font indicates significance.
CIs of observed and expected incidences were adjusted for multiple inferences using the Bonferroni method separately for each stratum.
CIs of observed and expected incidences and CIs of IRRs were adjusted for multiple inferences using the Bonferroni method, and P values were adjusted for multiple testing using the Bonferroni-Holm method.