Department of Medical Informatics, Biometry and Epidemiology, Chair of Biometry and Epidemiology, Friedrich-Alexander-University of Erlangen-Nuremberg, Waldstr. 6, D-91054 Erlangen, Germany.
J Clin Epidemiol. 2012 Sep;65(9):970-7. doi: 10.1016/j.jclinepi.2012.03.005. Epub 2012 Jun 27.
To assess and to evaluate possible effects arising from Web-based data collection on the results of a study.
We analyzed participants of the German Weight Control Registry (GWCR) of whom 328 chose to use Web-based questionnaires and 139 preferred to participate via a traditional postal survey. Furthermore, we included data of 212 individuals sampled independently from the general population who fulfilled the study's inclusion criteria-giving us the chance to differentiate between response bias (concerning Web-based data collection) and general selection bias (concerning participation in the GWCR).
In addition to selection bias (GWCR participants are overall better educated, more likely to live in a partnership, more often female, and older than the general population), we also found a substantial response bias: Participants using the Internet were younger, better educated, and more often male compared with participants preferring the paper-and-pencil version. However, after adjusting for these differences, we found no additional direct effect of Web-based data collection on any of the outcome variables.
Web-based epidemiologic studies still do not attract the same participants as postal surveys, even in highly industrialized countries. However, after adjusting for this bias, the same results can be expected.
评估和评估基于网络的数据收集对研究结果可能产生的影响。
我们分析了德国体重控制登记处（GWCR）的参与者，其中 328 人选择使用基于网络的问卷，139 人则更喜欢通过传统的邮寄调查参与。此外，我们还纳入了从一般人群中独立抽样的 212 名符合研究纳入标准的个体的数据，这使我们有机会区分响应偏差（关于基于网络的数据收集）和一般选择偏差（关于参与 GWCR）。
除了选择偏差（GWCR 参与者的整体教育程度更高，更有可能处于伴侣关系中，更多为女性，年龄也大于一般人群）之外，我们还发现了一个实质性的响应偏差：与喜欢纸笔版本的参与者相比，使用互联网的参与者更年轻、受教育程度更高、更多为男性。然而，在调整了这些差异后，我们发现基于网络的数据收集对任何结果变量都没有额外的直接影响。
即使在高度工业化的国家，基于网络的流行病学研究仍然不能吸引与邮寄调查相同的参与者。然而，在调整了这种偏差后，预计会得到相同的结果。
