Alternative modes for health surveillance surveys: an experiment with web, mail, and telephone

Web and mail surveys as complements to telephone surveys may help resolve concerns about declining participation in telephone surveys for public health surveillance. Little is known, however, about how responses obtained in Web surveys compare with those from mail or telephone surveys.

The Behavioral Risk Factor Surveillance System 2003 core interview was conducted in 3 survey modes: Web (n = 1143), mail (n = 836), and telephone (n = 2072). All 3 samples were drawn randomly. We compared respondent demographics and responses to 8 key questions on health conditions and risk behaviors (including asthma, diabetes, obesity, and HIV testing) across the 3 survey modes.

Demographic characteristics of mail and Web respondents varied considerably from those interviewed by telephone. The unadjusted prevalence of outcomes varied by survey mode. After adjustment for respondent demographic characteristics, there were still differences among survey modes in several of the health conditions and risk behaviors, although for some of these, the pattern was different for the unadjusted and adjusted results.

As health surveys take advantage of new technologies and moved towards mixed-mode designs, researchers need to test for and, if necessary, account for the effect of mode in the estimates they produce.