Low birth weight prevalence, odds ratios (95%CI) by social class, and RII by maternal factors and time, Scotland 1980–2000
| 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 | 3.2 | 1 | 3.3 | 1 | 3.0 | 1 | 2.9 | 1 | |||||
| II | 3.9 | 1.21 | (1.11, 1.32) | 3.9 | 1.19 | (1.09, 1.30) | 3.9 | 1.31 | (1.19, 1.43) | 3.8 | 1.34 | (1.22, 1.47) | |
| IIInm | 5.3 | 1.67 | (1.53, 1.82) | 5.16 | 1.56 | (1.43, 1.70) | 5.2 | 1.76 | (1.60, 1.93) | 5.2 | 1.84 | (1.67, 2.02) | |
| IIIm | 5.4 | 1.68 | (1.55, 1.83) | 5.2 | 1.60 | (1.47, 1.74) | 5.1 | 1.71 | (1.56, 1.87) | 5.1 | 1.81 | (1.65, 1.99) | |
| IV | 6.3 | 2.01 | (1.85, 2.19) | 6.3 | 1.96 | (1.80, 2.13) | 5.8 | 1.97 | (1.80, 2.16) | 6.1 | 2.17 | (1.98, 2.39) | |
| V | 6.9 | 2.19 | (2.01, 2.40 | 6.4 | 2.00 | (1.82, 2.20) | 6.2 | 2.11 | (1.92, 2.33) | 5.8 | 2.07 | (1.86, 2.31) | |
| Undetermined | 14.9 | 5.24 | (4.78, 5.73) | 7.8 | 2.48 | (2.26, 2.73) | 7.0 | 2.42 | (2.20, 2.66) | 7.4 | 2.70 | (2.47, 2.96) | |
| Total | 5.6 | 5.3 | 5.2 | 5.2 | |||||||||
| RII | p* | p* | p* | p* | |||||||||
| Overall | 2.89 | (2.73, 3.05) | 2.16 | (2.04, 2.29) | 2.09 | (1.97, 2.22) | 2.43 | (2.29, 2.58) | |||||
| Marital status | <0.001 | <0.001 | <0.001 | 0.01 | |||||||||
| Married | 2.86 | (2.68, 3.05) | 2.05 | (1.90, 2.20) | 1.96 | (1.81, 2.12) | 2.07 | (1.89, 2.27) | |||||
| Single | 1.67 | (1.44, 1.95) | 1.43 | (1.26, 1.62) | 1.34 | (1.20, 1.51) | 1.72 | (1.54, 1.91) | |||||
| Other | 1.59 | (1.26, 2.02) | 1.29 | (1.06, 1.58) | 1.42 | (1.18, 1.70) | 2.18 | (1.89, 2.52) | |||||
| Maternal age | <0.001 | <0.001 | <0.001 | <0.001 | |||||||||
| <20 | 1.56 | (1.33, 1.83) | 1.35 | (1.14, 1.60) | 1.07 | (0.88, 1.30) | 1.25 | (1.01, 1.55) | |||||
| 20–34 | 2.88 | (2.70, 3.07) | 2.10 | (1.96, 2.24) | 2.10 | (1.97, 2.25) | 2.31 | (2.16, 2.48) | |||||
| ⩾35 | 4.51 | (3.66, 5.56) | 3.26 | (2.65, 4.01) | 2.81 | (2.33, 3.38) | 3.78 | (3.22, 4.43) | |||||
| Maternal height | 0.013 | 0.12 | 0.58 | <0.001 | |||||||||
| <155 cm | 2.19 | (1.96, 2.44) | 1.80 | (1.60, 2.03) | 1.77 | (1.55, 2.02) | 1.89 | (1.64, 2.18) | |||||
| 155 cm–164 cm | 2.59 | (2.40, 2.80) | 1.84 | (1.70, 1.99) | 1.87 | (1.72, 2.03) | 2.16 | (1.99, 2.35) | |||||
| >164 cm | 2.91 | (2.56, 3.31) | 2.16 | (1.91, 2.45) | 2.03 | (1.81, 2.27) | 2.50 | (2.25, 2.78) | |||||
| Parity | <0.001 | <0.001 | <0.001 | <0.001 | |||||||||
| 0 | 2.17 | (2.01, 2.35) | 1.57 | (1.45, 1.70) | 1.54 | (1.42, 1.67) | 1.64 | (1.51, 1.78) | |||||
| 1–2 | 2.81 | (2.57, 3.07) | 2.28 | (2.07, 2.50) | 2.31 | (2.10, 2.54) | 2.92 | (2.66, 3.21) | |||||
| 3+ | 3.08 | (2.51, 3.77) | 2.11 | (1.71, 2.60) | 2.39 | (1.91, 2.98) | 3.08 | (2.48, 3.83) | |||||