The authors conducted a case-control study to determine whether risk factor
s for reading disability (RD) differentially affect boys and girls. The stu
dy population included all children born between 1976 and 1982 in Olmsted C
ounty, Minnesota (n = 5,701). A total of 303 RD cases were identified by us
ing intelligence quotient and achievement test scores collected from school
and medical records. After excluding those who met exclusion criteria (n =
869), controls consisted of all children not identified with RD (n = 4,529
). The authors examined the association between RD and potential risk facto
rs in boys and girls and confirmed their results in multivariable, logistic
regression models. Multivariable models indicated that girls of low birth
weight were more than twice as likely to be identified as RD (odds ratio (O
R) = 2.94, 95% confidence interval (Cl): 1.09, 6.25). Girls whose mothers h
ad 12 or fewer years of education were twice as likely to be identified as
RD (OR = 2.14, 95% Cl: 1.24, 3.72). However, girls whose fathers were aged
35 years or older at the time of birth were less likely to be identified as
RD (OR = 0.24, 95% Cl: 0.06, 0.92). Only 12 or fewer years of paternal edu
cation was associated with increased RD in boys (OR = 2.28, 95% Cl: 1.59, 3
.27). Boys and girls appear to be differentially susceptible to RD risk fac
tors, suggesting that the biologic processes leading to RD may differ betwe
en boys and girls.