Effect of hand versus electronic signatures on response rates in postal surveys: a randomised controlled trial among emergency physicians in Canada

Abstract

ObjectivesHand signatures offer a more authentic personalisation, which carries over to a sense of trust, although are costly and time-consuming when considering large postal surveys. The objective of this study was to compare response rates when using either hand-signed or electronic-signed letters in a postal survey.Design and settingWe embedded this randomised controlled trial within a national cross-sectional postal survey of emergency physicians in Canada. The survey aimed to describe current practice patterns with respect to primary headache disorders.ParticipantsWe randomly sampled 500 emergency physicians listed in the Scott’s Canadian Medical Directory, 2019 edition.InterventionsUsing computer-generated random numbers, physicians were allocated to receiving either hand-signed (n=250) or electronic signed (n=250) letters. The initial mailout contained a US$5 Tim Hortons coffee card with the invitation letter. Four reminders were sent to non-responders every 3 weeks. The same type of signature was used for the initial invitation and subsequent reminders.OutcomeThe primary outcome was the survey response rate.ResultsAmong 500 physicians invited, 32 invitations were undeliverable. Among the remaining 468 physicians, 231 had been allocated to the hand-signed group and 237 to the electronic signed group. The response rate in the hand-signed group was 87 (37.7%) vs 97 (40.9%) in the electronic-signed group (absolute difference in proportions −3.3%, 95% CI −12.1% to 5.6%).ConclusionThere was no significant difference in physician response rate between hand-signed and e-signed cover letter and reminder letters. Electronic signatures should be used in future postal surveys among physicians to save on time and labour without impacting response rates.