Associations between study arm and birth and early life outcomes*
| Birth and early life outcomes | Observed outcomes† | Unadjusted difference‡ | Adjusted difference§ | ||||||||
| Control (N=475) | Improved biomass (N=491) | LPG (N=340) | Improved biomass | LPG | Improved biomass | LPG | |||||
| Diff (95% CI) | P value | Diff (95% CI) | P value | Diff (95% CI) | P value | Diff (95% CI) | P value | ||||
| Birth weight—g | 2894±454 | 2904±458 | 2867±470 | 10 (–63 to 84) | 0.78 | −27 (–111 to 58) | 0.54 | −8 (–81 to 64) | 0.82 | −15 (–96 to 66) | 0.71 |
| Range | 1080–4340 | 1650–4500 | 1330–4030 | ||||||||
| Missing | 13 | 17 | 9 | ||||||||
| Head circumference—cm | 33.4±2.3 | 33.7±2.7 | 33.5±2.3 | 0.4 (–0.1 to 0.9) | 0.14 | 0.1 (–0.3 to 0.6) | 0.53 | 0.3 (–0.2 to 0.8) | 0.26 | 0.1 (–0.3 to 0.6) | 0.52 |
| Range | 22–43.8 | 21.5–45 | 25–44.5 | ||||||||
| Missing | 9 | 14 | 14 | ||||||||
| Birth length—cm | 46.7±4 | 46.8±3.1 | 46.2±3.7 | 0.1 (–0.9 to 1.1) | 0.84 | −0.5 (–1.6 to 0.6) | 0.37 | 0.1 (–0.9 to 1) | 0.9 | −0.5 (–1.6 to 0.6) | 0.40 |
| Range | 32.1–58 | 35–64 | 32.1–57 | ||||||||
| Missing | 4 | 10 | 10 | ||||||||
| Preterm birth —no. / total no. (%) | 24/475 (5) | 12/491 (2) | 16/340 (5) | 0.48 (0.25 to 0.93) | 0.03 | 0.93 (0.53 to 1.64) | 0.81 | 0.50 (0.26 to 0.95) | 0.03 | 0.94 (0.51 to 1.71) | 0.83 |
| Low birth weight—no. / total no. (%) | 79/462 (17) | 79/474 (17) | 58/331 (18) | 0.97 (0.73 to 1.3) | 0.86 | 1.02 (0.72 to 1.45) | 0.89 | 1.05 (0.79 to 1.4) | 0.74 | 1.02 (0.72 to 1.45) | 0.90 |
| Small for gestational age—no. / total no. (%) | 99/458 (22) | 109/473 (23) | 77/328 (23) | 1.09 (0.81 to 1.40) | 0.64 | 1.09 (0.82 to 1.43) | 0.56 | 1.13 (0.86 to 1.49) | 0.37 | 1.07 (0.81 to 1.42) | 0.61 |
| Neonatal death—no. / total no. (%) | 6/475 (1) | 4/491 (1) | 6/340 (2) | 0.64 (0.17 to 2.42) | 0.52 | 1.40 (0.47 to 4.15) | 0.55 | 0.61 (0.16 to 2.24) | 0.45 | 1.30 (0.43 to 3.96) | 0.65 |
*Plus–minus values are means±SD. Preterm birth defined as live birth≥28 and <37 completed weeks gestation. Low birth weight defined as birth weight<2500 g. Small for gestational defined as<10th percentile for gestational age. Neonatal death defined as infant death within 7 days of birth.
†Outcomes observed among live births with gestational age at 28 weeks or after. Missing values refer to missing values among the set of live births in each cluster.
‡Differences for continuous variables (birth weight, head circumference and birth length) come from linear regressions with cluster-robust SE estimates. Estimates shown represent difference in the mean of the study group and 95% CI as compared with the control group. Differences for categorical variables (pre-term birth, low birth weight, small for gestational age and neonatal death) come from modified (‘robust’) Poisson regressions with robust SE estimates using the ‘sandwich’ estimator (at the village level). Estimates shown represent risk ratios and 95% CIs as compared with the control group
§Differences replicate unadjusted models and additionally adjust for asset index, maternal body mass index, maternal age, parity, number of antenatal care visits and child sex.
LPG, liquefied petroleum gas.