An Assessment of Interrupted Telephone Service Adjustment (ITSA) in Random Digit Dialing (RDD) Telephone Surveys
Fahimi, M., Trofimovich, L., Levy, P. S., & Wells, H. E. (2004, August). An Assessment of Interrupted Telephone Service Adjustment (ITSA) in Random Digit Dialing (RDD) Telephone Surveys. Presented at , .
The exclusion of households without telephone is a source of systematicbias in telephone surveys. While lack of telephone service amonghouseholds is about five percent nationally, this rate is higher amonghouseholds of lower levels of socioeconomic status. Using theinterruption in telephone service as a surrogate for lack of service,we have used a weighting adjustment methodology to compensate fornon-telephone coverage in the 2003 Behavioral Risk Factors SurveillanceSystem (BRFSS). Inherent to this methodology is the assumption thatpersons living in households with interrupted telephone service aresimilar to those living in households without a telephone. In thispresentation, we discuss the construction of the ITSA for BRFSS andevaluate its merits. We will examine the extent of variance inflationthat results from applying this additional layer of adjustment andcontrast that against the potential gains in bias reduction on selectedvariables from BRFSS.