Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada
Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
BMJ Open. 2021 Sep 23;11(9):e052843. doi: 10.1136/bmjopen-2021-052843.
Response rates to physician surveys are typically low. The objective of this study was to determine the effect of a prenotification letter on the response rate of a postal survey of emergency physicians.
This was a substudy of a national, cross-sectional postal survey sent to emergency physicians in Canada. We randomised participants to either receive a postal prenotification letter prior to the survey, or to no prenotification letter.
A random sample of 500 emergency physicians in Canada. Participants were selected from the Canadian Medical Directory, a national medical directory which lists more than 99% of practising physicians in Canada.
Using computer-generated randomisation, physicians were randomised in a concealed fashion to receive a prenotification letter approximately 1 week prior to the survey, or to not receive a prenotification letter. All physicians received an unconditional incentive of a $3 coffee card with the survey instrument. In both groups, non-respondents were sent reminder surveys approximately every 14 days and a special contact using Xpresspost during the final contact attempt.
The primary outcome was the survey response rate.
201 of 447 eligible physicians returned the survey (45.0%). Of 231 eligible physicians contacted in the prenotification group, 80 (34.6%) returned the survey and among 237 eligible physicians contacted in the no-prenotification group, 121 (51.1%) returned the survey (absolute difference in proportions 16.5%, 95% CI 2.5 to 30.5, p=0.01).
Inclusion of a prenotification letter resulted in a lower response rate in this postal survey of emergency physicians. Given the added costs, time and effort required to send a prenotification letter, this study suggests that it may be more effective to omit the prenotification letter in physician postal surveys.
医生调查的回复率通常较低。本研究的目的是确定在对加拿大急诊医师进行的邮寄调查中，预先通知信对回复率的影响。
这是一项对加拿大全国性横断面邮寄调查的子研究。我们将参与者随机分为在调查前收到邮寄预先通知信的组或不收到预先通知信的组。
加拿大的 500 名急诊医师的随机样本。参与者从加拿大医学名录中选出，该名录是一个全国性的医学名录，列出了加拿大 99%以上的执业医师。
使用计算机生成的随机数对医生进行隐蔽分组，以便在调查前大约 1 周收到预先通知信，或不收到预先通知信。所有医生都收到了一份无条件的激励措施，即一张价值 3 加元的咖啡卡，随调查工具一起寄出。在两组中，未回复者大约每 14 天会收到后续调查，在最后一次联系尝试时，会使用 Xpresspost 发送特别联系。
主要结果是调查的回复率。
447 名符合条件的医生中有 201 名（45.0%）返回了调查。在预先通知组中联系的 231 名符合条件的医生中，有 80 名（34.6%）返回了调查，而在没有预先通知组中联系的 237 名符合条件的医生中，有 121 名（51.1%）返回了调查（比例的绝对差异为 16.5%，95%CI 2.5 至 30.5，p=0.01）。
在这项对加拿大急诊医师的邮寄调查中，预先通知信的加入导致回复率降低。考虑到发送预先通知信所需的额外成本、时间和精力，本研究表明，在医生邮寄调查中省略预先通知信可能更有效。
