Linear regression coefficients (in litres) for FEV1 and FVC according to African ancestry
| Models# | ||||
| 1 | 2 | 3 | 4 | |
| β (95% CI) | β (95% CI) | β (95% CI) | β (95% CI) | |
| FEV1 | ||||
| Males¶ | Adj-R2=3.3, p<0.001 | Adj-R2=31.4, p<0.001 | Adj-R2=32.1, p=0.007 | Adj-R2=34.6, p=0.030 |
| African ancestry % | ||||
| 0.0–5.2 | Reference | Reference | Reference | Reference |
| 5.3–25.8 | −0.17 (−0.26 – −0.08) | −0.08 (−0.15–0.00) | −0.07 (−0.15–0.00) | −0.06 (−0.14–0.01) |
| 25.9–87.9 | −0.31 (−0.43 – −0.20) | −0.20 (−0.30 – −0.10) | −0.15 (−0.25 – −0.05) | −0.13 (−0.23 – −0.03) |
| Females+ | Adj-R2=4.6, p<0.001 | Adj-R2=33.1, p<0.001 | Adj-R2=33.9, p<0.001 | Adj-R2=36.1, p<0.001 |
| African ancestry % | ||||
| 0.0–5.2 | Reference | Reference | Reference | Reference |
| 5.3–25.8 | −0.10 (−0.16 – −0.04) | −0.04 (−0.09–0.01) | −0.03 (−0.08–0.02) | −0.02 (−0.08–0.03) |
| 25.9–87.9 | −0.26 (−0.34 – −0.19) | −0.24 (−0.31 – −0.18) | −0.20 (−0.27 – −0.14) | −0.19 (−0.26 – −0.12) |
| FVC | ||||
| Males¶ | Adj-R2=4.5, p<0.001 | Adj-R2=37.8, p<0.001 | Adj-R2=39.1, p<0.001 | Adj-R2=40.7, p=0.002 |
| African ancestry % | ||||
| 0.0–5.2 | Reference | Reference | Reference | Reference |
| 5.3–25.8 | −0.22 (−0.32 – −0.11) | −0.09 (−0.18 – −0.01) | −0.09 (−0.17–0.00) | −0.09 (−0.17–0.00) |
| 25.9–87.9 | −0.46 (−0.59 – −0.32) | −0.30 (−0.41 – −0.19) | −0.24 (−0.35 – −0.12) | −0.21 (−0.32 – −0.09) |
| Females+ | Adj-R2=3.2, p<0.001 | Adj-R2=35.8, p<0.001 | Adj-R2=36.9, p<0.001 | Adj-R2=38.3, p<0.001 |
| African ancestry % | ||||
| 0.0–5.2 | Reference | Reference | Reference | Reference |
| 5.3–25.8 | −0.09 (−0.16 – −0.02) | −0.02 (−0.08–0.04) | −0.01 (−0.07–0.05) | −0.02 (−0.08–0.04) |
| 25.9–87.9 | −0.26 (−0.35 – −0.17) | −0.23 (−0.31 – −0.16) | −0.19 (−0.27 – −0.11) | −0.20 (−0.27 – −0.12) |
Note: for African ancestry categories, the statistical software creates dummy variables coded as 0 (reference) and 1 (category of African ancestry evaluated). FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity. #: model 1: African ancestry (crude model); model 2: model 1 plus height (cm); model 3: model 2 plus sitting height/height ratio and chest circumference (cm); model 4: model 3 plus current asset index (quintiles), current achieved schooling (categorised), current smoking, wheezing (in 2012), family income at birth (minimum salaries), maternal education at birth (complete years), birth weight (g), gestational age (weeks), asset index in quintiles (1984), maternal smoking during pregnancy (number of cigarettes), wheezing (from birth until 1984), and pneumonia (from birth until 1984). ¶ : n=927. +: n=943.