maximum total score of 300 (higher scores indicate more
developmental milestones reached). Cutoff scores were created
according to the ASQ manual, and scores that were 2
SDs less than the mean score of the respective subdomain
were considered subnormal. If questionnaires were not completely
answered, scores were adjusted according to the ASQ
manual.20
Behavior was assessed using the Strengths and Difficulties
Questionnaire (SDQ),21 which is directed at children aged
3 to 4 years. In theSDQ, 25 itemsin5 subscales are scored.Four
of these subscales—emotional difficulties score, conduct difficulties
score, hyperactivity difficulties score, and peer problems
score—are added together to forma total difficulties score
(based on 20 items; maximum score, 40; higher scores indicate
more difficulties). The fifth subscale, the prosocial score,
is evaluated separately (5 items; maximum score, 10; higher
scores indicate better prosocial behavior). A cutoff score was
defined according to the criteria given for borderline and abnormal
in the manual, Scoring the Informant-Rated Strengths
and Difficulties Questionnaire