Increasing Response Rates for Mailed Surveys of Medicaid Clients and Other Low-income Populations

Mailing surveys to low-income populations is often avoided because of concern about low response rates. In this study, the authors used a mailed survey of a low-income population to test whether 1. 00 or 2. 00 cash-response incentives were worth the expense and whether 2-day priority mail (2. 90 postage) would yield a sufficiently higher response rate than certified mail (1. 52 postage) to justify its cost. In 1994, 2, 243 randomly selected families in subsidized health care programs in Pierce County, Washington, were randomly sent no incentive, 1. 00, or 2. 00 in the first of three mailings. For the third mailing, nonrespondents were randomly assigned to receive either certified or 2-day priority mail. After 4 weeks, the response rates were 36. 7%, 48. 1%, and 50. 3% for the no-incentive, 1. 00, and 2. 00 groups, respectively. After three mailings, the cost per response was the lowest for the group that received 1. 00. The response rate for the certified mailing (28. 1%) was significantly higher than the rate for the more expensive priority mailing (21. 7%). No incentive-related bias was detected. The authors concluded that the most efficient protocol for this low-income population was to use a 1. 00 incentive in the first mailing and a certified third mailing.