Table 2.

Estimates of the differences in FEV₁ % predicted and Wisconsin chest X-ray score, using generalized estimating equation models with independent working correlation structures for prespecified risk factors for progression of lung disease, in models adjusted only for age and age at the time of diagnosis

	FEV1 % Predicted		WCXR Score
Risk Factor	Difference (SE)	P Value	Difference (SE)	P Value
Age, yr	−1.23 (0.19)	<0.001	1.62 (0.11)	<0.001
Sex (Ref: Male)	−3.55 (2.81)	0.2	−0.62 (1.65)	0.7
Genotype (Ref: Any CFTR class IV or V mutation)
F508del/F508del	−6.80 (4.07)	0.09	5.05 (1.46)	<0.001
F508del/any CFTR class I–III mutation	−13.52 (4.70)	0.004	6.35 (2.06)	0.002
Maternal education level (Ref: Did not graduate from high school)	−1.23 (4.20)	0.8	−3.96 (2.71)	0.1
Milwaukee CF center (Ref: Madison)	1.79 (2.84)	0.5	0.81 (1.58)	0.6
Old hospital	−5.29 (3.68)	0.2	2.29 (1.85)	0.2
Pancreatic insufficiency	−4.88 (4.95)	0.3	1.91 (2.96)	0.5
Height for age < 10th percentile	−12.37 (3.56)	<0.001	5.49 (1.78)	0.002
Age (wk) at diagnosis	0.04 (0.01)	<0.001	−0.03 (0.01)	<0.001
Recent hospitalization*	−11.48 (2.70)	<0.001	7.98 (1.17)	<0.001
Meconium ileus	−8.33 (3.34)	0.01	0.41 (2.04)	0.8
Staphylococcus aureus, >1 positive respiratory culture	0.99 (4.75)	0.8	−1.29 (0.81)	0.1
Pseudomonas aeruginosa, ever-positive respiratory culture	3.07 (3.26)	0.4	−1.15 (1.35)	0.4
P. aeruginosa, yr since initial positive culture	−0.16 (0.38)	0.7	0.45 (0.29)	0.1
P. aeruginosa, age at initial positive culture	0.05 (0.34)	0.9	−0.24 (0.23)	0.3
Mucoid P. aeruginosa, ever-positive respiratory culture	−5.13 (2.86)	0.07	5.86 (2.00)	0.004
Mucoid P. aeruginosa, years since initial positive culture	−1.33 (0.55)	0.02	1.35 (0.36)	<0.001
Mucoid P. aeruginosa, age at initial positive culture	0.52 (0.49)	0.3	−0.80 (0.24)	<0.001

Definition of abbreviations: CFTR = cystic fibrosis transmembrane conductance regulator; WCXR = Wisconsin chest X-ray.

^*Any hospitalizations within the 6 months before a measurement of FEV₁ or the same age as WCXR.