Postneonatal mortality due to respiratory illnesses is known to be inversely related to maternal age, but the role of young motherhood as a risk factor for respiratory morbidity in infants has not been explored thoroughly. A study was conducted in Tucson, Arizona, aimed at the incidence of lower respiratory tract illnesses during the first year of life. In this study, over 1200 infants were enrolled at birth between 1980 and 1984. The data shown in Table E1.27 are concerned with wheezing lower respiratory tract illnesses (wheezing LRI: no/yes).
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TABLE E1.27
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Boys
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Girls
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Maternal Age (years)
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No
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Yes
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No
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Yes
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21
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19
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8
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20
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7
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21-25
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98
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40
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128
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36
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26-30
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160
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45
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148
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42
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>30
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110
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20
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116
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25
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(a) For each of the two groups, boys and girls, choose the lowest age group as the baseline and calculate the odds ratio associated with each age group.
(b) For each of the two groups, boys and girls, calculate the generalized odds and give your interpretation. How does this result compare with those in part (a)?
(c) Compare the two generalized odds in part (b) and draw your conclusion.