Couper Mick P, Alexander Gwen L, Zhang Nanhua, Little Roderick J A, Maddy Noel, Nowak Michael A, McClure Jennifer B, Calvi Josephine J, Rolnick Sharon J, Stopponi Melanie A, Cole Johnson Christine
University of Michigan, Survey Research Center, Ann Arbor, 48106, USA.
J Med Internet Res. 2010 Nov 18;12(4):e52. doi: 10.2196/jmir.1430.
The Internet provides us with tools (user metrics or paradata) to evaluate how users interact with online interventions. Analysis of these paradata can lead to design improvements.
The objective was to explore the qualities of online participant engagement in an online intervention. We analyzed the paradata in a randomized controlled trial of alternative versions of an online intervention designed to promote consumption of fruit and vegetables.
Volunteers were randomized to 1 of 3 study arms involving several online sessions. We created 2 indirect measures of breadth and depth to measure different dimensions and dynamics of program engagement based on factor analysis of paradata measures of Web pages visited and time spent online with the intervention materials. Multiple regression was used to assess influence of engagement on retention and change in dietary intake.
Baseline surveys were completed by 2513 enrolled participants. Of these, 86.3% (n = 2168) completed the follow-up surveys at 3 months, 79.6% (n = 2027) at 6 months, and 79.4% (n = 1995) at 12 months. The 2 tailored intervention arms exhibited significantly more engagement than the untailored arm (P < .01). Breadth and depth measures of engagement were significantly associated with completion of follow-up surveys (odds ratios [OR] = 4.11 and 2.12, respectively, both P values < .001). The breadth measure of engagement was also significantly positively associated with a key study outcome, the mean increase in fruit and vegetable consumption (P < .001).
By exploring participants' exposures to online interventions, paradata are valuable in explaining the effects of tailoring in increasing participant engagement in the intervention. Controlling for intervention arm, greater engagement is also associated with retention of participants and positive change in a key outcome of the intervention, dietary change. This paper demonstrates the utility of paradata capture and analysis for evaluating online health interventions.
NCT00169312; http://clinicaltrials.gov/ct2/show/NCT00169312 (Archived by WebCite at http://www.webcitation.org/5u8sSr0Ty).
互联网为我们提供了工具（用户指标或辅助数据）来评估用户与在线干预措施的互动方式。对这些辅助数据的分析能够带来设计上的改进。
目的是探究在线干预中在线参与者参与度的特征。我们在一项关于旨在促进水果和蔬菜消费的在线干预措施不同版本的随机对照试验中分析了辅助数据。
志愿者被随机分配到3个研究组中的1组，参与多个在线课程。我们基于对访问网页的辅助数据测量以及在干预材料上花费的在线时间进行因子分析，创建了两个关于广度和深度的间接测量方法，以衡量项目参与度的不同维度和动态变化。使用多元回归来评估参与度对留存率和饮食摄入量变化的影响。
2513名登记参与者完成了基线调查。其中，86.3%（n = 2168）在3个月时完成了随访调查，79.6%（n = 2027）在6个月时完成，79.4%（n = 1995）在12个月时完成。两个量身定制的干预组的参与度明显高于未量身定制的组（P <.01）。参与度的广度和深度测量与随访调查的完成情况显著相关（优势比[OR]分别为4.11和2.12，P值均<.001）。参与度的广度测量也与一项关键研究结果——水果和蔬菜消费量的平均增加显著正相关（P <.001）。
通过探究参与者对在线干预措施的接触情况，辅助数据在解释量身定制对提高参与者在干预中的参与度的效果方面很有价值。在控制干预组的情况下，更高的参与度也与参与者的留存率以及干预的一个关键结果——饮食变化的积极改变相关。本文展示了辅助数据捕获和分析在评估在线健康干预措施方面的实用性。
NCT00169312；http://clinicaltrials.gov/ct2/show/NCT00169312（由WebCite存档于http://www.webcitation.org/5u8sSr0Ty）。
