CHARACTERISTICS OF SURVEY PARTICIPANTS WITH AND WITHOUT A TELEPHONE -FINDINGS FROM THE 3RD NATIONAL-HEALTH AND NUTRITION EXAMINATION SURVEY

This study examines the potential coverage bias in telephone surveys. Data were analyzed from the first phase of the third National Health a nd Nutrition and Examination Survey conducted from 1988 to 1991. In th at survey, 10,120 persons 17 years and older were interviewed and 9034 were examined. About 2.7% of respondents reported not having a teleph one. Differences in demographic and lifestyle variables, but not physi ological or anthropometric variables, existed between persons with a t elephone and those without one. Respondents without a telephone were m ore Likely to report that an impairment or health problems limited the ir work or activities. Compared with respondents with a telephone, tho se without one were more likely to be current smokers, to be less phys ically active, to never have had their brood pressure checked or have had it checked more than 5 years ago, and to never have had their chol esterol checked. Based on data from a 24-hour dietary recall, persons without a telephone consumed less vitamin A, Vitamin C, vitamin E, and carotene than did respondents with a telephone. However, prevalence e stimates of health characteristics obtained from telephone surveys in populations with high telephone coverage are unlikely to be seriously affected by coverage bias nor are conclusions of comparisons involving populations with low telephone coverage. Published by Elsevier Scienc e Inc.