Testing the Impact of Mixed-Mode Designs (Mail and Web) and Multiple Contact Attempts within Mode (Mail or Web) on Clinician Survey Response.

OBJECTIVE: To compare response rate and nonresponse bias across two mixed-mode survey designs and two single-mode designs.

DATA SOURCES: This experiment was embedded in a clinician survey of knowledge and attitudes regarding HPV vaccination (n = 275).

STUDY DESIGN: Clinicians were randomly assigned one of two mixed-mode (mail/web or web/mail) or single-mode designs (mail-only/web-only). Differences in response rate and nonresponse bias were assessed.

PRINCIPAL FINDINGS: Using a multiple-contact protocol increased response, and sending a web survey first provided the more rapid response. Overall, the mixed-mode survey designs generated final response rates approximately 10 percentage points higher than their single-mode counterparts, although only the final response differences between the mail-only and web/mail conditions attained statistical significance (32.1 percent vs. 48 percent, respectively; p = .005). Observed differences did not result in nonresponse bias.

CONCLUSIONS: Results support mixing modes of survey administration and web-based data collection in a multiple contact survey data collection protocol.