Effect of prize draw incentive on the response rate to a postal survey of obstetricians and gynaecologists: a randomised controlled trial. [ISRCTN32823119

Sharon H Moses,T Justin Clark

doi:10.1186/1472-6963-4-14

Sharon H Moses, T Justin Clark

Open Access

https://doi.org/10.1186/1472-6963-4-14

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Abstract

BackgroundResponse rates to postal questionnaires are falling and this threatens the external validity of survey findings. We wanted to establish whether the incentive of being entered into a prize draw to win a personal digital assistant (PDA) would increase the response rate for a national survey of consultant obstetricians and gynaecologists.MethodsA randomised controlled trial was conducted. This involved sending a postal questionnaire to all Consultant Obstetricians and Gynaecologists in the United Kingdom. Recipients were randomised to receiving a questionnaire offering a prize draw incentive (on response) or no such incentive.ResultsThe response rate for recipients offered the prize incentive was 64% (461/716) and 62% (429/694) in the no incentive group (relative rate of response 1.04, 95% CI 0.96 – 1.13)ConclusionThe offer of a prize draw incentive to win a PDA did not significantly increase response rates to a national questionnaire survey of consultant obstetricians and gynaecologists.

Highlights

Response rates to postal questionnaires are falling and this threatens the external validity of survey findings
There is evidence that response rates to surveys are declining in general practice [1] and this trend may be reflected in hospital based medicine
This is of concern as the external validity of the findings from these surveys is dependent upon adequate response rates [1]

Summary

Methods

Recipients were randomised to receiving a questionnaire offering a prize draw incentive (on response) or no such incentive. Recipients were randomised to receive a questionnaire containing a covering letter offering the incentive of entry to a prize draw to win a personal digital assistant (PDA) or no incentive. Based on the response rate from a previous gynaecological questionnaire [5] we assumed that inclusion of a prize draw incentive would increase the proportion of responders by 10% from 60% to 70%. This meant that the sample size (1410) had 95 % power (alpha = 0.05, beta = 0.05).

Results

Discussion

Conclusion