Investigating the attitudes, beliefs, behaviors, and concerns of physicians via survey is vitally important given their role in the provision of health care and shaping the health care system. However, response rates to surveys of physicians have been found to be about 10 percentage points lower than surveys of nonphysicians (Asch, Jedrziewski, and Christakis 1997
). Moreover, and as is the case with surveys of their patient and general population counterparts, there is evidence that response rates to physician surveys may be declining. In a review of response rates to mailed physician surveys from 1986 to 1995, Cummings, Savitz, and Konrad (2001)
found rates to be rather constant. More recent investigations, however, point to a potential downward canting of response. Looking at response rates to surveys of pediatricians between 1994 and 2002, Cull et al. (2005)
observed that the response rates to the 50 surveys they examined declined significantly during that timeframe, from an average response rate of 70 percent observed before 1998 and earlier to an average rate of 63 percent since then. In order to improve (or at least maintain) response rates to physician surveys and ensure that the perspectives of physicians who respond are representative of all physicians invited to participate, it is incumbent on health survey researchers to use the best methods for achieving that goal. Such is the focus of the investigation described herein.
To increase response rates, household surveys often turn to mixed-mode designs whereby instruments are designed to be administered via mail, web, telephone, and/or in-person and respondents are allowed to respond to the form most appropriate for them (de Leeuw 2005
). The application of mixed-mode designs to physician surveys seems natural given that low response rates to single-mode physician surveys are common (about 52– 54 percent for large surveys, on average; see Asch, Jedrziewski, and Christakis 1997
; Cummings, Savitz, and Konrad 2001
). Additionally, some have demonstrated that selecting survey techniques that work well on physicians with differing characteristics (such as specialty and metropolitan residence) is important (Moore and Tarnai 2002
). A review of the relevant literature suggests that one particular mode combination, mail and web, might prove useful in increasing response rates to physician surveys.
First, physicians, unlike their general population and patient counterparts, generate response rates to mailed surveys that are equal to those produced by personal or telephone interviews (Kellerman and Herold 2001
). This finding, coupled with the large cost savings associated with mailed physician surveys vis-à-vis interviews (Shosteck and Fairweather 1979
), underscores the attractiveness of a mailed survey as a method of collecting survey data from physicians. Second, while web (e-mail) surveys have a number of advantages to mailed surveys such as even lower
cost, ability to capture data in an electronic format, speed of response, and data quality (Schleyer and Forrest 2000
; Braithwaite et al. 2003
; Akl et al. 2005
), response rates to web surveys can be lower than those of mailed surveys (McMahon et al. 2003; Losch
, Thompson, and Lutz 2004
; Akl et al. 2005
). It is plausible that combining the two modes might allow the strengths of one to offset the limitations of the other.
Finally, there is recent evidence that combining web and mailed surveys may enhance the coverage of the survey to a broader mix of physicians because the profile of providers responding electronically can be somewhat different from those responding to a mail survey. Losch, Thompson, and Lutz (2004)
found that when given a choice to respond to a survey about colorectal cancer screening by web or mail, primary care physicians in general internal medicine and male physicians were more likely to respond to the web version than their family practitioner, OB/GYN, and female counterparts. Again, this suggests that the web and mail mode combination might enhance the representation of one's responding sample by allowing different types of physicians to respond to their preferred data collection method.
The current investigation is a response to specific requests to test web and mail mixed-mode designs in the context of a physician survey (VanGeest and Johnson 2001
; McMahon et al. 2003
; Cull et al. 2005
) by comparing two different mixed-mode designs representing two combinations of web and mail surveys. To better understand which ordering of web and mail mode is most effective in producing the highest response rate, fastest rate of return, and least nonresponse bias (an often overlooked measure of data quality), we conducted an experiment where physicians were randomly assigned to receive either an initial mailed survey with a web survey follow-up to nonrespondents, or its converse—an initial web survey followed by a mailed survey to nonrespondents.