Associations between SHS exposure (defined as measured plasma cotinine >0.05 ng/mL or above the limit of quantification if higher than 0.05 ng/mL) and asthma outcomes by study (as proxy for race/ethnicity) using multiple imputation data to account for missing NMR values
| Asthma outcomes | OR (95% CI) | |
| Study | ||
| GALA II | SAGE II | |
| Asthma exacerbations in the previous 12 months* | 1.38 (0.95 to 2.01) | 1.27 (0.74 to 2.19) |
| Asthma control (binary outcome)† | 1.27 (0.84 to 1.91) | 2.16 (1.27 to 3.67) |
| Not well controlled versus controlled | 1.21 (0.66 to 2.22) | 1.58 (0.87 to 2.91) |
| Very poorly controlled versus controlled | 1.33 (0.80 to 2.22) | 2.77 (1.51 to 5.00) |
↵*Asthma exacerbations assessed as a combined variable for any exacerbations (hospitalisations, ER visits, prescription of oral steroids) versus none.
↵†Asthma control assessed as binary outcome with a combined ‘not well controlled’ and ‘very poorly controlled’ category compared with controlled asthma.
ER, emergency room; GALA, Gene-environments and Admixture in Latino Americans; NMR, nicotine metabolite ratio; SAGE, Study of African Americans, Asthma, Genes and Environments; SHS, secondhand smoke.