SURVEY METHODOLOGY

The 2000 Iowa Child and Family Household Health Survey was a telephone interview conducted with a stratified random sample of 3,200 families with children in Iowa. The interview included approximately 125 questions, depending on the number of questions relevant to the family being interviewed. The survey instrument was developed by the research team after existing survey instruments such as the National Survey of American Families (NSAF) and the National Health Interview Survey (NHIS) had been evaluated.2,3

To identify families with children in Iowa, researchers began with a random list of phone numbers provided by a private vendor. To allow for regional comparisons, 400 interviews were completed in each of eight regions of the state. Each region consisted of multiple counties with two exceptionsPolk and Scott counties were single-county regions. The design of this study yielded a representative sample of families with children in Iowa. To make statewide estimates, the survey results were weighted and post-stratified using the county-level 2000 US Census data.4 The survey process began with a screening question to determine if the number dialed reached the home of a family with children. If it had, the adult most knowledgeable about the health and health care of a randomly selected child under age 18 in the household was asked to complete the interview.

The dispositions of calls made to complete the 3,200 interviews were as follows:

  • Number completing the interview: 3,241
  • Number of refusals or unable to complete interview: 1,349
  • Participation rate: 71%

The telephone interviews were conducted between May and October 2000 by the Center for Social and Behavioral Research at the University of Northern Iowa. The University of Northern Iowa Human Subjects review board approved the protocol regarding the telephone interview portion of this study.

In any telephone-based survey, there is a possibility that results may be biased because those without telephones are not interviewed; people without telephones may have different health conditions and health care needs than those with telephones. In Iowa, it is estimated that three percent of households do not have telephones.5

2 See http://newfederalism.urban.org/nsaf/

3 See http://www.cdc.gov/nchs/nhis.htm

4 See http://factfinder.census.gov/home/en/sf1.html

5 200 "Telephone Information by State." Survey Sampling, Inc., One Post Road, Fairfield, CT 06430