Social class | 1980–1984 | 1985–1989 | 1990–1994 | 1995–2000 | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
% | OR | 95%CI | % | OR | 95%CI | % | OR | 95%CI | % | OR | 95%CI | ||
*p for interaction term. | |||||||||||||
I | 3.4 | 1 | 3.9 | 1 | 3.9 | 1 | 3.7 | 1 | 1 | ||||
II | 4.0 | 1.20 | (1.10, 1.31) | 4.2 | 1.09 | (1.00, 1.19) | 4.4 | 1.12 | (1.03, 1.21) | 4.5 | 1.21 | (1.11, 1.32) | |
IIInm | 4.9 | 1.48 | (1.36, 1.61) | 5.1 | 1.34 | (1.23, 1.46) | 5.4 | 1.40 | (1.29, 1.53) | 5.4 | 1.47 | (1.35, 1.60) | |
IIIm | 4.8 | 1.42 | (1.31, 1.54) | 5.0 | 1.30 | (1.20, 1.41) | 5.1 | 1.32 | (1.22, 1.44) | 5.4 | 1.46 | (1.34, 1.58) | |
IV | 5.7 | 1.71 | (1.57, 1.85) | 5.5 | 1.45 | (1.33, 1.57) | 5.4 | 1.40 | (1.29, 1.52) | 5.9 | 1.60 | (1.47, 1.74) | |
V | 5.8 | 1.75 | (1.60, 1.91) | 5.5 | 1.45 | (1.32, 1.59) | 5.5 | 1.43 | (1.30, 1.56) | 5.7 | 1.56 | (1.41, 1.73) | |
Undetermined | 14.4 | 4.78 | (4.37, 5.23) | 7.1 | 1.91 | (1.74, 2.09) | 6.5 | 1.70 | (1.56, 1.85) | 6.9 | 1.90 | (1.75, 2.07) | |
Total | 5.2 | 5.0 | 5.2 | 5.4 | |||||||||
RII | p* | p* | p* | p* | |||||||||
Overall | 2.45 | (2.31, 2.59) | 1.60 | (1.51, 1.70) | 1.52 | (1.44, 1.61) | 1.75 | (1.65, 1.86) | |||||
Marital status | <0.001 | 0.001 | 0.004 | 0.18 | |||||||||
Married | 2.31 | (2.16, 2.46) | 1.48 | (1.38, 1.59) | 1.43 | (1.32, 1.54) | 1.65 | (1.51, 1.79) | |||||
Single | 1.76 | (1.51, 2.06) | 1.14 | (1.00, 1.29) | 1.11 | (0.99, 1.26) | 1.45 | (1.30, 1.62) | |||||
Other | 1.45 | (1.12, 1.88) | 1.20 | (0.97, 1.49) | 1.27 | (1.05, 1.53) | 1.50 | (1.30, 1.73) | |||||
Maternal age | <0.001 | 0.002 | 0.001 | 0.005 | |||||||||
<20 | 1.48 | (1.26, 1.74) | 1.12 | (0.95, 1.33) | 1.03 | (0.84, 1.25) | 1.39 | (1.12, 1.73) | |||||
20–34 | 2.35 | (2.20, 2.52) | 1.55 | (1.45, 1.66) | 1.50 | (1.41, 1.61) | 1.66 | (1.55, 1.78) | |||||
⩾35 | 3.08 | (2.50, 3.80) | 1.69 | (1.37, 2.08) | 1.69 | (1.40, 2.03) | 2.12 | (1.81, 2.48) | |||||
Maternal height | 0.54 | 0.39 | 0.27 | <0.001 | |||||||||
<155 cm | 2.15 | (1.89, 2.44) | 1.38 | (1.20, 1.58) | 1.32 | (1.13, 1.53) | 1.54 | (1.31, 1.80) | |||||
155 cm–164 cm | 2.36 | (2.19, 2.56) | 1.55 | (1.43, 1.68) | 1.43 | (1.32, 1.55) | 1.69 | (1.56, 1.84) | |||||
>164 cm | 2.33 | (2.07, 2.62) | 1.51 | (1.35, 1.69) | 1.55 | (1.40, 1.72) | 1.71 | (1.55, 1.87) | |||||
Parity | 0.01 | <0.001 | <0.001 | <0.001 | |||||||||
0 | 2.07 | (1.91, 2.25) | 1.24 | (1.14, 1.35) | 1.25 | (1.15, 1.36) | 1.31 | (1.20, 1.42) | |||||
1–2 | 2.48 | (2.27, 2.72) | 1.81 | (1.65, 1.99) | 1.69 | (1.54, 1.85) | 2.04 | (1.86, 2.23) | |||||
3+ | 2.44 | (2.00, 2.98) | 1.63 | (1.32, 2.00) | 1.38 | (1.12, 1.70) | 2.17 | (1.77, 2.66) |