Data analyses. For purposes of data analyses, only one child per family was included in tests of associations with child's gender and child's age. This "focal child" was the first child younger than 72 months old, as described by the parent. Also, for purposes
of data analysis, the child's insurance status was categorized as "public" or "private or self-pay." All analyses were conducted using Stata 11.0 software (StataCorp, College Station, Texas, USA).