Most of the analysis variables are either based on single variables from the questionnaire (Blumberg et al., 2008) or are self-explanatory. Insurance type, family structure, and household income relative to Federal Poverty Level are based on derived variables available on the public-use file and described in the methodology report (Blumberg et al., 2008). Variables that need further explanation are described here.
Child-level characteristics — For race/ethnicity, non-Hispanic multiple-race children are grouped with non-Hispanic Native American/Alaskan Native and non-Hispanic Native Hawaiian/Pacific Islander into “non-Hispanic other.” Hispanic multiple-race children are grouped with “Hispanic.” Siblings are defined as other children in the household irrespective of biological or adopted status.
Adoption date variables — Years since adoption is calculated as the difference between age in months at interview and age in months at adoption, divided by 12, and rounded to nearest whole integer. Year of adoption is derived from the century-month code for date of interview, age in months at adoption, and age in months at interview by calculating the number of months between adoption and interview and subtracting that sum from the century-month code for date of interview to derive the century-month code for date of adoption.
CSHCN Screener items — Children qualify on a screener item as CSHCN if they experience a health consequence that is due to a medical or other condition that has lasted or is expected to last at least 12 months.
Type of health conditions — The number of health conditions (0-16) is based on a battery of questions assessing whether the child currently had any of 16 specific health conditions (Blumberg et al., 2008). Seven conditions were not prevalent enough for reliable estimation by adoption type and are grouped together as “other condition:” Down syndrome, diabetes, heart problems, blood problems, cystic fibrosis, cerebral palsy, and muscular dystrophy. The remaining nine conditions are reported separately.
Functional status — Bodily function difficulties are indicated if the parent reported that the child had any difficulty with seeing, hearing, breathing, swallowing or digesting, blood circulation, or chronic pain. Activity/participation difficulties are indicated by any difficulty with taking care of oneself, coordination, manual dexterity, learning, or communicating. Other emotional/ behavioral difficulties are indicated by any difficulty with anxiety/depression, behavior problems, or making friends (Blumberg et al., 2008).
Key Indicators — MCHB, with assistance from NCHS and the Child and Adolescent Health Measurement Inititative (CAHMI), has developed a set of indicators from the NS-CSHCN that measure the key concepts in the survey. National and State-level estimates of these indicators for 2005-2006 were released in The National Survey of Children with Special Health Care Needs Chartbook 2005-2006 (US DHHS, 2007). Our indicators of health status, insurance, access to health care, impact on the family, and need and unmet need for services are based on the key indicators and are coded in the same manner as in that chartbook. More information on the key indicators is available at the CAHMI Data Resource Center website: (http://www.childhealthdata.org/content/Default.aspx).