Sinai Health System, Mount Sinai Hospital, Toronto, ON, Canada.
University of Toronto, Toronto, ON, Canada.
BMC Med Res Methodol. 2018 Jun 20;18(1):59. doi: 10.1186/s12874-018-0524-8.
Web-based surveys have become increasingly popular but response rates are low and may be prone to selection bias. How people are invited to participate may impact response rates and needs further study as previous evidence is contradictory. The purpose of this study was to determine whether response to a web-based survey of healthcare workers would be higher with a posted or an emailed invitation. We also report results of the pilot study, which aims to estimate the percentage of adults vaccinated against influenza who report recurrent systemic adverse events (the same systemic adverse event occurring successively following receipt of influenza vaccines).
The pilot study was conducted in November 2016 in Toronto, Canada. Members of a registry of adults (18 years and older and predominantly healthcare workers) who volunteered to receive information regarding future studies about influenza were randomly assigned to receive either an email or postal invitation to complete a web-based survey regarding influenza vaccinations. Non-respondents received one reminder using the same mode of contact as their original invitation.
The overall response rate was higher for those sent the invitation by email (34.8%) than by post (25.8%; p < 0.001) and for older versus younger participants (p < 0.001). Of those who responded, 387/401 had been vaccinated against influenza at least once since adulthood. Of those responding to the question, 70/386 (18.1%) reported a systemic adverse event after their most recent influenza vaccine including 22 (5.7%) who reported a recurring systemic event. Systemic adverse events were reported more often by males 18-49 years old than by other groups (p = 0.01). Recurrent systemic adverse events were similar by age and sex with muscle ache being the most commonly reported recurrent reaction. More respondents who reported only a local adverse event (93.1%) planned to be vaccinated again next year than those with a systemic adverse event (69.7%; p = 0.04).
In this convenience sample of registry volunteers, response rates were generally low, but were higher for the emailed than posted invitations and for older than younger adults.
基于网络的调查越来越受欢迎，但回应率较低，且可能容易受到选择偏差的影响。邀请人们参与的方式可能会影响回应率，这需要进一步研究，因为之前的证据存在矛盾。本研究的目的是确定针对医疗保健工作者的基于网络的调查，以张贴或电子邮件邀请的方式，哪种方式的回应率会更高。我们还报告了试点研究的结果，该研究旨在估计报告反复出现全身不良反应（在接种流感疫苗后连续发生相同的全身不良反应）的成年人中流感疫苗接种率。
试点研究于 2016 年 11 月在加拿大多伦多进行。登记册中的成年人（18 岁及以上，主要是医疗保健工作者）自愿接收有关流感未来研究的信息，他们被随机分配以接收电子邮件或邮寄邀请，以完成有关流感疫苗接种的网络调查。未回复的人会收到一封与原始邀请相同方式的提醒。
与通过邮件收到邀请的人（34.8%）相比，通过邮件收到邀请的人（25.8%；p<0.001）和老年人（p<0.001）的总体回应率更高。在做出回应的人中，有 401 人中有 387 人自成年以来至少接种过一次流感疫苗。在回答问题的人中，有 70/386（18.1%）人在最近一次流感疫苗接种后报告了全身不良反应，包括 22 人（5.7%）报告了反复发生的全身事件。18-49 岁的男性报告全身不良反应的频率高于其他群体（p=0.01）。全身不良反应的报告在年龄和性别上相似，肌肉疼痛是最常见的反复反应。更多报告仅出现局部不良反应的人（93.1%）计划明年再次接种疫苗，而有全身不良反应的人（69.7%；p=0.04）。
在本研究中，登记册志愿者的回应率普遍较低，但电子邮件邀请比邮寄邀请高，老年人比年轻人高。
