Western Australian Institute for Medical Research, Sir Charles Gairdner Hospital, University of Western Australia, B Block, Hospital Avenue, Nedlands, Perth, Western Australia 6009, Australia.
J Clin Epidemiol. 2013 Dec;66(12):1417-21. doi: 10.1016/j.jclinepi.2013.03.007. Epub 2013 Jun 2.
To test the impact of an advance letter on response and cooperation rates in a nationwide telephone survey, given previous inconsistent results.
Within the context of a larger telephone survey, 1,000 Australian households were randomly selected to take part in this trial. Half were randomly allocated to receive an advance letter, whereas the remainder did not receive any advance communication. Response and cooperation rates were compared between the two groups.
A total of 244 interviews were completed, 134 of which were with households that had been sent an advance letter. Intention-to-treat analysis revealed no significant difference in response between those who had received a letter and those who had not (26.8% vs. 22.0%, respectively). In addition, there was no significant difference between the groups in terms of either cooperation (78.4% vs. 79.7%) or response rate (56.3% vs. 57.9%), and no clear differences emerged in terms of the demographic characteristics of the two groups.
An advance letter was not seen to be effective in increasing response or cooperation rates in a nationwide telephone survey. Researchers should consider alternative methods of increasing participation in telephone surveys.
鉴于先前结果不一致，测试在全国性电话调查中预先通知信对回应率和合作率的影响。
在一项更大的电话调查背景下，随机选择 1000 户澳大利亚家庭参与这项试验。其中一半被随机分配到接收预先通知信的组，而其余的则没有收到任何预先沟通。比较两组之间的回应和合作率。
共完成了 244 次访谈，其中 134 次是与已收到预先通知信的家庭进行的。意向治疗分析显示，收到信和未收到信的两组之间的回应率没有显著差异（分别为 26.8%和 22.0%）。此外，两组在合作率（78.4%对 79.7%）或回应率（56.3%对 57.9%）方面也没有显著差异，两组的人口统计学特征也没有明显差异。
预先通知信并未显著提高全国性电话调查的回应率或合作率。研究人员应考虑其他方法来提高电话调查的参与度。
