Abstract

To what extent do survey nonresponse and coverage problems bias estimates of physical activity? Research has focused on social desirability as a cause of observed bias but there are relatively few studies of nonresponse and coverage. I analyze data from a survey designed to allow estimation of nonresponse bias using a two-phase sampling design that resamples nonrespondents from an initial wave of telephone and IVR (interactive voice response) interviewing for follow-up face-to-face interviews. Both initial and nonresponse interview waves included measures of physical activity frequency and duration. Estimates are compared between first-round respondents and those from follow-up interviews of nonrespondents, accounting for mode and other design elements. Telephone, but not IVR, interviews were found to include bias from two sources. Findings suggest that coverage is a cause of bias in the measure of frequency of physical activity but nonresponse may bias the measure of physical activity duration.

摘要

调查无响应和覆盖问题在多大程度上会偏向身体活动的估计？研究的重点是社会期望作为观察到的偏见的一个原因，但对无反应和覆盖率的研究相对较少。我分析了一项调查中的数据，该调查旨在使用两阶段抽样设计对不答复者从最初的电话和 IVR（交互式语音响应）访谈中重新抽样，以进行后续面对面访谈的估计。初始和无响应访谈波都包括对身体活动频率和持续时间的测量。将第一轮受访者的估计值与非受访者的后续访谈中的估计值进行比较，考虑模式和其他设计元素。电话采访被发现包括来自两个来源的偏见，但不包括 IVR。