Survey Methods to Optimize Response Rate in the National Dental Practice-Based Research Network

Surveys of health professionals typically have low response rates, and these rates have been decreasing in the recent years. We report on the methods used in a successful survey of dentist members of the National Dental Practice-Based Research Network. The objectives were to quantify the (1) increase in response rate associated with successive survey methods, (2) time to completion with each successive step, (3) contribution from the final method and personal contact, and (4) differences in response rate and mode of response by practice/practitioner characteristics. Dentist members of the network were mailed an invitation describing the study. Subsequently, up to six recruitment steps were followed: initial e-mail, two e-mail reminders at 2-week intervals, a third e-mail reminder with postal mailing a paper questionnaire, a second postal mailing of paper questionnaire, and staff follow-up. Of the 1,876 invited, 160 were deemed ineligible and 1,488 (87% of 1,716 eligible) completed the survey. Completion by step: initial e-mail, 35%; second e-mail, 15%; third e-mail, 7%; fourth e-mail/first paper, 11%; second paper, 15%; and staff follow-up, 16%. Overall, 76% completed the survey online and 24% on paper. Completion rates increased in absolute numbers and proportionally with later methods of recruitment. Participation rates varied little by practice/practitioner characteristics. Completion on paper was more likely by older dentists. Multiple methods of recruitment resulted in a high participation rate: Each step and method produced incremental increases with the final step producing the largest increase.