Table B.1.
Individual and environmental predictors of total transport CO2 emissions, car CO2 allocated to driver only (N = 3474).
| Variable | Level | Median | Regression coefficients (βs) and 95% CI for standardised log-transformed carbon |
|||
|---|---|---|---|---|---|---|
| Min-adjusteda |
Multivariable 1 |
Multivariable 2 |
Multivariable 3 |
|||
| R2 = 0.22 | R2 = 0.29 | R2 = 0.37 | ||||
| Sex | Female | 14.3 | 0⁎⁎⁎ | 0⁎⁎⁎ | 0⁎⁎⁎ | 0⁎⁎⁎ |
| Male | 24.2 | 0.25 (0.17, 0.34) | 0.22 (0.14, 0.31) | 0.18 (0.10, 0.26) | 0.21 (0.14, 0.28) | |
| Age | 18–34 years | 12.9 | 0⁎⁎⁎ | 0⁎⁎⁎ | 0⁎⁎⁎ | 0⁎⁎⁎ |
| 35–49 years | 26.8 | 0.42 (0.30, 0.53) | 0.16 (0.04, 0.28) | 0.14 (0.03, 0.25) | 0.13 (0.03, 0.24) | |
| 50–64 years | 22.5 | 0.32 (0.21, 0.43) | 0.22 (0.09, 0.34) | 0.25 (0.12, 0.37) | 0.23 (0.11, 0.35) | |
| >65 years | 11.9 | −0.18 (−0.30, −0.06) | 0.02 (−0.15, 0.19) | 0.05 (−0.12, 0.22) | 0.06 (−0.11, 0.22) | |
| Ethnicity | White | 18.0 | 0 | 0 | 0 | 0 |
| Non-White | 16.5 | −0.10 (−0.32, 0.12) | 0.06 (−0.16, 0.28) | 0.10 (−0.11, 0.31) | 0.14 (−0.05, 0.33) | |
| Any child under 16 | No | 16.2 | 0⁎ | 0 | 0 | 0 |
| Yes | 24.6 | 0.15 (0.04, 0.27) | 0.08 (−0.03, 0.19) | 0.09 (−0.01, 0.20) | 0.04 (−0.06, 0.14) | |
| Education | Degree | 24.6 | 0⁎⁎⁎ | 0⁎⁎⁎ | 0⁎⁎⁎ | 0⁎⁎⁎ |
| A-level | 17.8 | −0.34 (−0.47, −0.22) | −0.15 (−0.28, −0.03) | −0.14 (−0.26, −0.02) | −0.12 (−0.23, −0.01) | |
| GCSE | 16.7 | −0.37 (−0.50, −0.25) | −0.23 (−0.35, −0.11) | −0.23 (−0.34, −0.12) | −0.14 (−0.24, −0.04) | |
| No formal | 10.5 | −0.58 (−0.69, −0.47) | −0.33 (−0.45, −0.22) | −0.31 (−0.42, −0.20) | −0.23 (−0.34, −0.12) | |
| Annual household income | >£40,000 | 31.4 | 0⁎⁎⁎ | 0⁎⁎ | 0⁎ | 0 |
| £20–40,000 | 21.7 | −0.22 (−0.33, −0.11) | −0.10 (−0.21, 0.02) | −0.03 (−0.14, 0.07) | −0.02 (−0.12, 0.09) | |
| <£20,000 | 9.5 | −0.64 (−0.75, −0.53) | −0.26 (−0.38, −0.14) | −0.18 (−0.29, −0.06) | −0.11 (−0.22, 0.00) | |
| Housing tenure | Owned | 21.9 | 0⁎⁎⁎ | 0⁎⁎⁎ | 0⁎⁎⁎ | 0 |
| Privately rented | 7.8 | −0.51 (−0.65, −0.36) | −0.33 (−0.47, −0.18) | −0.17 (−0.32, −0.03) | −0.07 (−0.20, 0.06) | |
| Council rented | 3.4 | −0.82 (−0.97, −0.68) | −0.44 (−0.60, −0.29) | −0.35 (−0.51, −0.20) | −0.07 (−0.24, 0.09) | |
| Other | 14.3 | −0.10 (−0.35, 0.16) | 0.05 (−0.17, 0.26) | 0.05 (−0.16, 0.27) | 0.13 (−0.06, 0.33) | |
| Employment status | Full-time | 30.5 | 0⁎⁎⁎ | 0⁎⁎⁎ | 0⁎⁎⁎ | 0⁎⁎⁎ |
| Part-time | 21.5 | −0.18 (−0.28, −0.08) | −0.14 (−0.24, −0.04) | −0.07 (−0.17, 0.03) | −0.07 (−0.16, 0.02) | |
| Student | 2.6 | −0.83 (−1.03, −0.63) | −0.67 (−0.88, −0.46) | −0.62 (−0.82, −0.42) | −0.45 (−0.64, −0.26) | |
| Retired | 12.5 | −0.47 (−0.61, −0.33) | −0.37 (−0.50, −0.24) | −0.13 (−0.29, 0.03) | −0.14 (−0.30, 0.02) | |
| Home duties | 12.3 | −0.53 (−0.73, −0.32) | −0.43 (−0.62, −0.23) | −0.27 (−0.48, −0.06) | −0.20 (−0.39, 0.00) | |
| Other | 3.4 | −1.00 (−1.18, −0.82) | −0.67 (−0.88, −0.47) | −0.46 (−0.67, −0.25) | −0.36 (−0.56, −0.15) | |
| Site | Southampton | 10.7 | 0⁎⁎⁎ | 0 | 0 | |
| Cardiff | 18.9 | 0.22 (0.12, 0.32) | 0.01 (−0.11, 0.13) | 0.02 (−0.10, 0.13) | ||
| Kenilworth | 23.5 | 0.40 (0.29, 0.50) | 0.10 (−0.02, 0.23) | 0.11 (−0.01, 0.23) | ||
| Urban/rural status | Urban | 17.1 | 0⁎⁎⁎ | 0 | 0 | |
| Rural | 33.3 | 0.42 (0.27, 0.58) | 0.18 (0.00, 0.37) | 0.14 (−0.03, 0.32) | ||
| Population density | Change per 10 people per hectare | −0.05 (−0.06, −0.03)⁎⁎⁎ | −0.02 (−0.03, 0.00)⁎ | −0.01 (−0.02, 0.00) | ||
| Home-work distance | 0–2 km/no comm. | 9.6 | −0.18 (−0.31, −0.05) | −0.04 (−0.18, 0.09) | −0.05 (−0.18, 0.08) | |
| 2–5 km | 13.1 | 0⁎⁎⁎ | 0⁎⁎⁎ | 0⁎⁎⁎ | ||
| 5–10 km | 25.7 | 0.39 (0.22, 0.55) | 0.26 (0.09, 0.42) | 0.20 (0.05, 0.35) | ||
| 10–20 km | 36.7 | 0.74 (0.59, 0.89) | 0.56 (0.42, 0.69) | 0.45 (0.33, 0.58) | ||
| ⩾20 km or variable | 65.2 | 0.83 (0.68, 0.98) | 0.71 (0.57, 0.85) | 0.61 (0.47, 0.75) | ||
| Home-retail distance | Change per kilometer | 0.07 (0.05, 0.09)⁎⁎⁎ | −0.01 (−0.03, 0.02) | −0.02 (−0.04, 0.01) | ||
| Cars per adult in household | No cars | 1.5 | −0.79 (−0.91, −0.67) | −0.60 (−0.73, −0.47) | ||
| <1 Car per adult | 13.5 | 0⁎⁎⁎ | 0⁎⁎⁎ | |||
| ⩾1 Cars per adult | 28.5 | 0.57 (0.49, 0.65) | 0.39 (0.32, 0.47) | |||
| Any adult bike | No | 14.9 | 0 | 0⁎⁎ | ||
| Yes | 20.8 | 0.01 (−0.08, 0.10) | −0.11 (−0.19, −0.03) | |||
⁎
p < 0.05.
⁎⁎
p < 0.01.
⁎⁎⁎
p < 0.001.
a
Minimally-adjusted analyses adjust for age and sex only, multivariable analyses adjust for all variables in column. Outcome is standardised log-transformed CO2 (no unit due to transformation to log([CO2/mean(CO2)] + 0.01)).