Table 3.

Multivariable linear regression model of baseline risk factors associated with best FEV₁% predicted at age 6–7 years

Risk Factor*	Mean Difference in Best FEV1% Predicted†	95% Confidence Interval	P Value
Age at enrollment on study	−1.3	−2.4, –0.3	0.01
Weight percentile < 10% during year of enrollment	−5.3	−9.1, –1.5	0.006
P. aeruginosa positive during year of enrollment	−2.8	−5.7, 0.0	0.05
Crackles or wheeze during year of enrollment	−5.7	−9.4, –1.9	0.003
Mother’s education high school or less	−4.2	−7.3, –1.2	0.007
Mother smoked during pregnancy	−4.4	−8.8, 0.1	0.055

^*The multivariable model was based on observations for 461 participants.

^†For age at enrollment, the mean difference in best FEV₁% predicted reflects the mean difference per 1-year increase in age. For categorical covariates, the mean difference in best FEV₁% predicted reflects the mean difference relative to the reference category. Reference categories included weight percentile equal to or greater than 10%, P. aeruginosa negative, no sounds on chest examination, mother’s education beyond high school, and no smoking during pregnancy.