Table 4.
Change in weight-for-gestational age Z scores with an IQR increase in PM2·5, black carbon, and carbon monoxide
| Model | Estimate (95% CI) | p value | Akaike's Information Criterion | |
|---|---|---|---|---|
| Adjusted associations | ||||
| PM2·5 | Linear | −0·03 (−0·06 to 0·00) | 0·380 | 7021 |
| PM2·5 | Log linear | −0·04 (0·09 to 0·01) | 0·100 | 7023 |
| Black carbon | Linear | −0·05 (−0·08 to −0·01) | 0·006 | 6591 |
| Black carbon | Log linear | −0·06 (−0·10 to −0·01) | 0·019 | 6593 |
| Carbon monoxide | Linear | −0·003 (−0·023 to 0·017) | 0·780 | 7215 |
| Carbon monoxide | Log linear | 0·02 (−0·02 to 0·06) | 0·239 | 7214 |
| Crude associations* | ||||
| PM2·5 | Linear | −0·04 (−0·07 to −0·01) | 0·013 | 7161 |
| PM2·5 | Log linear | −0·06 (−0·11 to −0·01) | 0·020 | 7162 |
| Black carbon | Linear | −0·05 (−0·09 to −0·02) | 0·003 | 6708 |
| Black carbon | Log linear | −0·06 (−0·11 to −0·02) | 0·007 | 6710 |
| Carbon monoxide | Linear | −0·003 (−0·024 to 0·017) | 0·739 | 7342 |
| Carbon monoxide | Log linear | 0·02 (−0·02 to 0·06) | 0·323 | 7341 |
All models adjusted for mother's education, baseline BMI, nulliparity, diet diversity, food insecurity score, second-hand smoke, baseline haemoglobin, age, neonate sex, and ten randomisation strata. For the linear model, the IQR for PM2·5 was 74·51, for black carbon was 7·30, and for carbon monoxide was 1·68. On the log scale, IQRs were 1·04 for PM2.5, 0·85 for black carbon, and 1·40 for carbon monoxide.
*
Estimates for change in IQR from a crude model adjusting only for randomisation strata.