Maternal age at birth of child | Model 1 RR (95.0% CI) | Model 2 RR (95.0% CI) | Model 3 RR (95.0% CI) | Model 4 RR (95.0% CI) |
---|---|---|---|---|
Model 1 adjusted for sex and year of birth (child characteristics). Model 2 adjusted for sex, year of birth, type of community, and housing (external environment). Model 3 adjusted for sex, year of birth, type of community, housing, education of grandmother, income of grandmother in quartiles, welfare payments to grandmother, and ethnicity (social background). Model 4 adjusted for sex, year of birth, type of community, housing, education of grandmother, income of grandmother in quartiles, welfare payments to grandmother, ethnicity, lone parent household, alcohol, substance misuse and/or psychiatric illness in parents (family environment). | ||||
12–17 | 1.6 (1.4 to 1.8) | 1.6 (1.4 to 1.8) | 1.4 (1.3 to 1.6) | 1.4 (1.2 to 1.6) |
18–19 | 1.5 (1.4 to 1.6) | 1.4 (1.4 to 1.5) | 1.4 (1.3 to 1.5) | 1.4 (1.3 to 1.5) |
20–24 | 1.2 (1.2 to 1.3) | 1.2 (1.2 to 1.3) | 1.2 (1.2 to 1.2) | 1.2 (1.2 to1.2) |
25–28 | 1.1 (1.1 to 1.2) | 1.1 (1.1 to 1.2) | 1.1 (1.1 to 1.1) | 1.1 (1.1 to 1.1) |
29–32 | 1.0 (1.0 to 1.1) | 1.0 (1.0 to 1.1) | 1.0 (1.0 to 1.1) | 1.0 (1.0 to 1.1) |
33–55 | 1 | 1 | 1 | 1 |