Effects of enhanced calling efforts on response rates, estimates of health behavior, and costs in a telephone health survey using random-digit dialing.

Public health researchers frequently rely on random-digit dialing (RDD) telephone surveys in monitoring trends in health behavior and evaluating health promotion interventions. RDD response rates have declined during the past decade, and cost-effective methods to increase response rates are needed. The authors evaluated two levels of enhanced calling efforts in an RDD survey of cancer-related health behavior in the State of Washington.