Methods: After piloting, a random sample of 600 dentists registered to practice under the UK General Dental Council (GDC) were emailed with a personalised hyperlink to a University hosted web-based survey on dentists’ views of direct patient access to dental hygienists and therapists. A second email reminder to non-responders was followed by mailing of a paper questionnaire, and a final reminder/thank you email to the whole sample. Demographic data were compared for the three groups (online, postal and non-responders). Sample size calculation was based on likely experience of teamworking.
Results: The pilot of 52 research-active General Dental Practitioners (GDPs) achieved a 82% response rate (RR) - 26 online, 15 on paper. In the main sample, 10 individuals were ineligible (not practicing, moved address): RR=26% (N=155: 74 online; 81 postal). There were no significant differences across online, postal and non-responders by gender, UK country of employment, UK/non-UK dental school attended (X2test), or years since qualification (one way ANOVA). X2 and t-tests were conducted using a response/no response dichotomy, with similar results. However, specialists were under-represented (3/44 responded: X2=8.98, df=2, p=0.002).
Conclusion: The overall RR was poor, but comparable to other surveys of dentists involving postal and/or online designs. Comparing demographic variables available for the whole sample found little evidence of significant response bias. The expectation that younger dentists may be more likely to use the online option was not supported. The study was innovative in its combination of use of email addresses derived from the GDC register and mixed online/postal delivery, and the value of the register for such survey methods was supported. Targeting of GDPs and use of financial or other incentives may have improved RR.
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