Multivariable associations between doctor-diagnosed childhood pneumonia-pleurisy and transfer factor in middle age
| Episodes of pneumonia/pleurisy† | Complete case (n) | Transfer factor of the lung at ages 45 and 53 (z-score (SD, 95% CI))‡§ | |||||
| TLco | Kco | VA | |||||
| (z-score (SD, 95% CI)) | P value | (z-score (SD, 95% CI)) | P value | (z-score (SD, 95% CI)) | P value | ||
| At age 45 | |||||||
| 0 | 925 | Ref | Ref | Ref | |||
| ≥1 | 202 | +0.14 (−0.04 to +0.3) | 0.127 | +0.29 (+0.1 to +0.5)** | 0.002 | −0.12 (−0.3 to +0.04) | 0.131 |
| 1–2 | 182 | +0.11 (−0.1 to +0.3) | 0.208 | +0.25 (+0.1 to +0.4)* | 0.011 | −0.08 (−0.2 to +0.1) | 0.336 |
| >2 | 20 | +0.31 (−0.2 to +0.8) | 0.234 | +0.66 (+0.1 to +1.1)* | 0.012 | −0.48 (−0.9 to 0.04)* | 0.033 |
| At age 53 | |||||||
| 0 | 1986 | Ref | Ref | Ref | |||
| ≥1 | 307 | +0.08 (−0.03 to +0.2) | 0.149 | +0.17 (+0.04 to +0.3)** | 0.008 | −0.08 (−0.2 to +0.04) | 0.196 |
| 1–2 | 280 | +0.07 (−0.05 to +0.2) | 0.227 | +0.15 (+0.02 to +0.3)* | 0.020 | −0.07 (−0.2 to +0.05) | 0.251 |
| >2 | 27 | +0.20 (−0.2 to +0.6) | 0.287 | +0.33 (−0.1 to +0.7) | 0.098 | −0.14 (−0.5 to +0.2) | 0.458 |
*P<0.05, **p<0.01, ***p<0.001.
†≥1 and >2 episodes refer to childhood pneumonia/pleurisy-ever and recurrent pneumonia/pleurisy in the main text, respectively.
‡Multivariable adjustments include sampling weights, maternal/paternal smoking, socioeconomic status (paternal occupation, rurality of primary school) and history of breast/bottle feeding.
§If a statistical interaction is present, stratified results have been presented in the main text and correspond to online supplementary table E5 (by current childhood asthma), online sup[plementary table E6 (by participant sex) and online supplementary table E7 (by never/ever smoking).
Kco, carbon monoxide transfer coefficient; Ref, reference; TLco, transfer factor of the lung for carbon monoxide; VA, alveolar volume.