|
Gestational age/Birth weight
|
1995-2005
|
2005
|
|---|
|
Rate (95 % CI)
|
Rate Ratio (95 % CI)
|
Rate (95 % CI)
|
Rate Ratio (95 % CI)
|
|---|
|
GA (weeks)
|
≥22
|
Canada
|
3.1 (3.1–3.2)
|
1.26 (1.23–1.29)
|
3.2 (2.9–3.4)
|
1.47 (1.36–1.59)
|
|
USA
|
3.8 (3.7–3.8)
|
1.50 (1.49–1.51)
|
3.5 (3.5–3.6)
|
1.65 (1.62–1.67)
|
|
Denmark
|
3.4 (3.3–3.5)
|
1.35 (1.30–1.41)
|
3.3 (2.8–3.7)
|
1.51 (1.32–1.73)
|
|
Finland
|
2.5 (2.4–2.6)
|
1.00
|
2.2 (1.8–2.6)
|
1.00
|
|
Iceland
|
2.1 (1.7–2.5)
|
0.83 (0.67–1.01)
|
1.4 (0.5–3.0)
|
0.65 (0.24–1.41)
|
|
Norway
|
2.4 (2.3–2.5)
|
0.97 (0.92–1.02)
|
1.9 (1.5–2.3)
|
0.87 (0.72–1.06)
|
|
Sweden
|
2.2 (2.1–2.3)
|
0.89 (0.86–0.93)
|
1.4 (1.2–1.7)
|
0.67 (0.57–0.79)
|
|
≥24
|
Canada
|
2.4 (2.3–2.5)
|
1.05 (1.03–1.08)
|
2.4 (2.2–2.7)
|
1.24 (1.14–1.36)
|
|
USA
|
2.8 (2.8–2.8)
|
1.22 (1.22–1.23)
|
2.6 (2.5–2.6)
|
1.32 (1.30–1.35)
|
|
Denmark
|
3.2 (3.0–3.3)
|
1.39 (1.34–1.45)
|
3.0 (2.6–3.4)
|
1.53 (1.32–1.76)
|
|
Finland
|
2.3 (2.2–2.4)
|
1.00
|
2.0 (1.6–2.4)
|
1.00
|
|
Iceland
|
1.6 (1.2–2.0)
|
0.68 (0.53–0.86)
|
0.9 (0.3–2.4)
|
0.48 (0.13–1.22)
|
|
Norway
|
2.1 (2.0–2.2)
|
0.92 (0.87–0.97)
|
1.5 (1.2–1.9)
|
0.79 (0.63–0.97)
|
|
Sweden
|
2.0 (2.0–2.1)
|
0.90 (0.86–0.94)
|
1.4 (1.1–1.6)
|
0.70 (0.58–0.82)
|
|
≥28
|
Canada
|
1.7 (1.6–1.7)
|
0.82 (0.79–0.85)
|
1.6 (1.4–1.7)
|
0.86 (0.77–0.96)
|
|
USA
|
1.9 (1.8–1.9)
|
0.91 (0.91–0.92)
|
1.7 (1.6–1.7)
|
0.91 (0.89–0.93)
|
|
Denmark
|
2.5 (2.4–2.6)
|
1.23 (1.18–1.29)
|
2.2 (1.9–2.6)
|
1.22 (1.03–1.43)
|
|
Finland
|
2.0 (1.9–2.1)
|
1.00
|
1.8 (1.5–2.2)
|
1.00
|
|
Iceland
|
1.0 (0.8–1.4)
|
0.51 (0.38–0.68)
|
0.5 (0.1–1.7)
|
0.26 (0.03–0.92)
|
|
Norway
|
1.6 (1.5–1.7)
|
0.78 (0.73–0.83)
|
1.2 (1.0–1.6)
|
0.67 (0.52–0.85)
|
|
Sweden
|
1.6 (1.5–1.6)
|
0.77 (0.73–0.81)
|
1.0 (0.8–1.2)
|
0.53 (0.43–0.65)
|
|
BW (grams)
|
≥500
|
Canada
|
2.8 (2.8–2.9)
|
1.23 (1.21–1.27)
|
2.7 (2.5–3.0)
|
1.40 (1.29–1.52)
|
|
USA
|
3.3 (3.2–3.3)
|
1.42 (1.41–1.42)
|
3.0 (3.0–3.1)
|
1.53 (1.51–1.57)
|
|
Denmark
|
3.3 (3.1–3.4)
|
1.42 (1.36–1.48)
|
3.1 (2.7–3.5)
|
1.56 (1.35–1.79)
|
|
Finland
|
2.3 (2.2–2.4)
|
1.00
|
2.0 (1.6–2.4)
|
1.00
|
|
Iceland
|
2.0 (1.6–2.5)
|
0.87 (0.70–1.07)
|
1.2 (0.4–2.7)
|
0.59 (0.19–1.39)
|
|
Norway
|
2.2 (2.1–2.4)
|
0.97 (0.92–1.02)
|
1.7 (1.4–2.1)
|
0.87 (0.71–1.07)
|
|
Sweden
|
2.1 (2.0–2.2)
|
0.92 (0.89–0.96)
|
1.4 (1.2–1.6)
|
0.71 (0.59–0.83)
|
|
≥1000
|
Canada
|
1.7 (1.6–1.7)
|
1.10 (1.07–1.14)
|
1.4 (1.3–1.6)
|
1.04 (0.93–1.17)
|
|
USA
|
1.8 (1.8–1.8)
|
1.17 (1.16–1.18)
|
1.6 (1.6–1.6)
|
1.18 (1.15–1.21)
|
|
Denmark
|
2.5 (2.4–2.6)
|
1.64 (1.57–1.72)
|
2.3 (1.9–2.7)
|
1.67 (1.41–1.97)
|
|
Finland
|
1.5 (1.4–1.6)
|
1.00
|
1.4 (1.1–1.7)
|
1.00
|
|
Iceland
|
0.9 (0.7–1.3)
|
0.62 (0.45–0.83)
|
0.5 (0.1–1.7)
|
0.34 (0.04–1.24)
|
|
Norway
|
1.5 (1.4–1.6)
|
1.00 (0.94–1.06)
|
1.2 (1.0–1.6)
|
0.92 (0.72–1.16)
|
|
Sweden
|
1.6 (1.5–1.7)
|
1.06 (1.01–1.12)
|
1.0 (0.8–1.2)
|
0.75 (0.61–0.91)
|
|
All live births
|
Canada
|
3.8 (3.7–3.8)
|
1.50 (1.47–1.53)
|
3.9 (3.7–4.2)
|
1.83 (1.71–1.96)
|
|
USAa
|
4.4 (4.4–4.4)
|
1.76 (1.75–1.76)
|
4.2 (4.2–4.3)
|
1.96 (1.93–1.99)
|
|
Denmark
|
3.5 (3.3–3.6)
|
1.38 (1.33–1.43)
|
3.3 (2.9–3.8)
|
1.55 (1.35–1.77)
|
|
Finland
|
2.5 (2.4–2.6)
|
1.00
|
2.2 (1.8–2.6)
|
1.00
|
|
Iceland
|
2.1 (1.7–2.6)
|
0.84 (0.69–1.03)
|
1.4 (0.5–3.1)
|
0.65 (0.24–1.41)
|
|
Norway
|
2.6 (2.5–2.8)
|
1.05 (1.00–1.10)
|
2.1 (1.7–2.5)
|
0.96 (0.79–1.15)
|
|
Sweden
|
2.2 (2.1–2.3)
|
0.89 (0.85–0.93)
|
1.4 (1.2–1.7)
|
0.67 (0.57–0.79)
|
- GA gestational age and BW birth weight. Rates are expressed per 1,000 infants at risk. Only births with gestational age <22 weeks excluded from the rate calculation for births ≥22 weeks i.e., births with unknown gestational age included in the calculations. Calculations of rates for births ≥28 weeks and birth weight ≥500 g and ≥1000 g were carried out in a similar manner. Finland was used as the reference category for calculation of rate ratios
- aUS rates are based on live births with GA ≥20 completed weeks
