Table 3.

CF Infants: Pulmonary Function at End of Respiratory Virus Season, Results of Multiple Regression Analyses

Dependent VariableIndependent VariableRegression (β) CoefficientsStandard ErrorStandardized CoefficientP
V′maxFRCIntercept−7260−1.2NS
Postseason
 V′max FRC baseline0.410.142.9.01
 RSV infection22440.5NS
 LRI194662.9.01
 Male165473.5.004
 SES score3.41.13.2.001
 LRI × male interaction−32967−4.9<.001
 LRI × RSV interaction−24086−2.8.02
R2 (adj.) = 0.78; df(total) = 20; P (model) = <.001
FRCIntercept −18476−2.4.04
Postseason
 FRC baseline1.90.36.4<.001
 RSV infection−4636−1.3NS
 Adenovirus culture positive117383.1.01
 LRI−8637−2.3<.05
 Male−4632−1.4NS
 Length change (cm)124.42.8.02
 Day care145542.7.03
 LRI × RSV interaction196623.2.01
R2 (adj.) = 0.76; df (total) = 18; P (model) = .003
  • Continuous variables: V′maxFRC at baseline; V′maxFRC at postseason; FRC at baseline; FRC at postseason; change of length over season, in centimeters; SES score (Hollingshead).

    Dichotomous variables: RSV infection: 0 = negative; 1 = positive culture or four-fold rise in antibody titer; LRI: 0 = no; 1 = yes one or more LRI; Adenovirus culture: 0 = negative; 1 = positive culture; Male: 0 = no; 1 = yes; Day care: 0 = no; 1 = yes attended daycare; LRI × RSV interaction: 0 = other; 1 = positive for both RSV and one or more LRI; LRI × male interaction: 0 = other; 1 = males with one or more LRI.