Telephone coverage and measurement of health risk indicators: data from the National Health Interview Survey.

OBJECTIVES: This study compared health behavior variables for all US households and households with telephones to measure the potential impact of telephone coverage on estimates from telephone surveys. METHODS: Data were derived from the 1991 through 1994 version of the National Health Interview Survey. RESULTS: Ninety-five percent of respondents lived in households with telephones. Differences in health indicators were small (< 1%) in comparisons between all households and those with telephones. Results were similar when only respondents below the poverty level were included. CONCLUSIONS: Telephone noncoverage effects appear to be small, supporting the use of telephone surveys for health risk behavior surveillance with most population groups.