Leibniz Institute for Prevention Research and Epidemiology - BIPS, Achterstrasse 30, 28359, Bremen, Germany.
BMC Med Res Methodol. 2020 Jul 9;20(1):187. doi: 10.1186/s12874-020-01073-0.
With declining response proportions in population-based research the importance of evaluating the effectiveness of measures aimed at improving response increases. We investigated whether an additional flyer with information about the study influences participation in a follow-up questionnaire and the time participants take to send back filled questionnaire.
In a trial embedded within the German National Cohort we compared responses to invitations for a follow-up questionnaire either including a flyer with information about the cohort study or not including it. Outcomes of interest were participation in the follow-up (yes vs. no) and time to response (in days). We analyzed paradata from baseline recruitment to account for differences in recruitment history between participants.
Adding a flyer to invitations did neither influence the likelihood of participation in the follow-up (OR 0.94, 95% CI: 0.80, 1.11), nor the time it took participants to return completed questionnaires (β̂ = 1.71, 95% CI: - 1.01, 4.44). Subjects who, at baseline, needed to be reminded before eventually participating in examinations and subjects who scheduled three or more appointments until eventually completing baseline examinations were less likely to complete the follow-up questionnaire and, if they did, took more time to complete questionnaires.
Evaluating the effectiveness of measures aimed at increasing response can help to improve the allocation of usually limited resources. Characteristics of baseline recruitment can influence response to follow-up studies and therefore information about recruitment history (i.e., paradata) might prove useful to tailor follow-up recruitments to those who were difficult to recruit during baseline. To this end, however, it is necessary to routinely and meticulously collect paradata during recruitment.
随着基于人群的研究中回应比例的下降，评估旨在提高回应率的措施的有效性变得越来越重要。我们研究了在研究邀请中增加一份关于研究的传单是否会影响参与者对后续问卷调查的参与度，以及参与者发送填完的问卷所需的时间。
在德国国家队列研究中进行的一项试验中，我们比较了邀请参与者参加后续问卷调查时是否包含关于队列研究的传单的两种情况。感兴趣的结果是参与后续调查（是与否）和回复时间（以天为单位）。我们分析了基线招募时的元数据，以考虑到参与者招募历史之间的差异。
在邀请中添加传单既不会影响参与后续调查的可能性（OR 0.94，95%CI：0.80，1.11），也不会影响参与者返回完成问卷所需的时间（β̂ = 1.71，95%CI：-1.01，4.44）。在基线时需要被提醒后才最终参加检查的受试者，以及需要预约三次或更多次才能最终完成基线检查的受试者，不太可能完成后续问卷调查，如果他们完成了，那么完成问卷所需的时间也更长。
评估旨在提高回应率的措施的有效性有助于改善通常有限资源的分配。基线招募的特征可能会影响对后续研究的回应，因此关于招募历史的信息（即元数据）可能有助于根据招募期间的困难程度来调整后续招募。然而，为此，有必要在招募过程中系统地、细致地收集元数据。
