First Mailings Versus Follow-Up Mailings: Do the Same Strategies Have the Same Effects?
McFarlane, E. S., Murphy, J., & Olmsted, M. G. (2008, May). First Mailings Versus Follow-Up Mailings: Do the Same Strategies Have the Same Effects?. Presented at AAPOR 2008, New Orleans, LA.
A number of studies have shown that stamped return envelopes elicit higher response rates than business reply or metered mail in mail surveys of physicians (Kellerman and Harold, 2001; Shiono & Klebenhoff, 1991; Urban, Anderson, and Tseng, 1993). Most studies, though, have only tested the use of postage stamps on return envelopes with the fist mailing or for the mailings over all. What impact on response rates, if any, do postage stamps have on nonresponse follow-up mailings and are they still cost-effective? To address this issue, researchers at RTI International tested the effects of using stamped return envelopes on a series of survey mailings in a national survey of board certified physicians conducted as part of the “America’s Best Hospitals” project for U.S. News & World Report. On the first mailing to physicians, surveys sent with a stamped return envelope achieved a 19.1% response rate compared to a 15.3% response rate for surveys sent with a business reply envelope (BRE) instead. The difference of 3.7% was statistically significant. The use of postage stamps on the first mailing was cost-effective overall, despite being more expensive for the first mailing. The increase in response rates for the stamp group reduced the number of follow-ups needed, offsetting the initial cost of the postage stamps. However, we did not find that postage stamps on return envelopes improved response rates compared to BREs on three follow-up mailings, and as a result increased costs. The results of this study suggest that a tailored design approach that uses different strategies for different mailings within a study may be the most effective for increasing response rates while minimizing costs.