通过提供参与模式选择来提高参与率：两项随机对照试验
Improving participation rates by providing choice of participation mode: two randomized controlled trials.
作者信息
Heijmans Naomi, van Lieshout Jan, Wensing Michel
机构信息
Radboud University Medical Centre, Nijmegen, Scientific Institute for Quality of Healthcare, PO 9101, 6500, HB, Nijmegen, The Netherlands.
出版信息
BMC Med Res Methodol. 2015 Apr 2;15:29. doi: 10.1186/s12874-015-0021-2.
BACKGROUND
Low participation rates reduce effective sample size, statistical power and can increase risk for selection bias. Previous research suggests that offering choice of participation mode can improve participation rates. However, few head-to-head trials compared choice of participation mode using telephone interviews and postal questionnaires as modes of interest. Aiming to explore effects of choice of participation, two randomized controlled trials were performed comparing participation rates of patients provided with and without choice of participation mode, using interviews and questionnaires as participation modes.
METHODS
Two trials were embedded in a larger study on cardiovascular risk management in primary care. Patients with a chronic cardiovascular condition recruited for the larger study were invited to participate in an additional survey on social networks, using invitations with and without choice of participation mode. Primary outcome was participation rate. Other outcomes of interest were participation rate conditional on willingness to participate, and initial willingness to participate. In trial 1 we compared outcomes after choice of participation mode (interview or questionnaire) with invitations for participation in a telephone interview. In Trial 2 results for choice of participation mode were compared with postal questionnaires.
RESULTS
In Trial 1 no differences were found in participation rates (65% vs 66%, p = 0.853) although conditional participation rate was highest for interviews (90% vs 72%, p < .01). Initial willingness to participate was higher when choice of participation mode was provided (90% versus 73%, p < .01). In Trial 2 participation rate and conditional participation rate was higher when choice of participation mode was provided (59% vs 46%, p < .01 and 66% vs 53%, p < .01, respectively). No differences were found for initial willingness to participate (90% vs 86%, p = 0.146).
CONCLUSION
Offering choice of participation mode had benefit on participation rates compared to invitations to participate in questionnaires, but not when compared to invitations to participate in telephone interviews.
TRIAL REGISTRATION
Current Controlled Trials ISRCTN89237105 .
背景
低参与率会降低有效样本量、统计效力，并可能增加选择偏倚的风险。先前的研究表明，提供参与方式的选择可以提高参与率。然而，很少有直接比较以电话访谈和邮寄问卷作为感兴趣的参与方式的头对头试验。为了探索参与方式选择的影响，进行了两项随机对照试验，比较了有和没有参与方式选择的患者的参与率，采用访谈和问卷作为参与方式。
方法
两项试验嵌入了一项关于初级保健中心血管风险管理的更大规模研究。为该更大规模研究招募的患有慢性心血管疾病的患者被邀请参加一项关于社交网络的额外调查，使用有和没有参与方式选择的邀请函。主要结局是参与率。其他感兴趣的结局是基于参与意愿的参与率以及初始参与意愿。在试验1中，我们将参与方式选择（访谈或问卷）后的结局与电话访谈的参与邀请函进行了比较。在试验2中，将参与方式选择的结果与邮寄问卷进行了比较。
结果
在试验1中，参与率没有差异（65%对66%，p = 0.853），尽管访谈的条件参与率最高（90%对72%，p < 0.01）。当提供参与方式选择时，初始参与意愿更高（90%对73%，p < 0.01）。在试验2中，当提供参与方式选择时，参与率和条件参与率更高（分别为59%对46%，p < 0.01和66%对53%，p < 0.01）。初始参与意愿没有差异（90%对86%，p = 0.146）。
结论
与参与问卷的邀请函相比，提供参与方式的选择对参与率有好处，但与参与电话访谈的邀请函相比则不然。
试验注册
当前对照试验ISRCTN89237105 。
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