Department of Preventive Medicine and Public Health, Tokyo Medical University, Tokyo, Japan.
J Epidemiol. 2010;20(6):446-52. doi: 10.2188/jea.je20100062. Epub 2010 Sep 18.
Differences in the characteristics of respondents and nonrespondents to a survey can be a cause of selection bias. The aim of this study was to determine the sociodemographic and lifestyle characteristics of respondents to a field-based accelerometry survey.
A cross-sectional mail survey was sent to 4000 adults (50% male; age 20 to 69 years) who were randomly selected from the registries of residential addresses of 4 cities in Japan. There were 1508 respondents (responding subsample) to the initial questionnaire. A total of 786 participants from the responding subsample also agreed to wear an accelerometer for 7 days (accelerometer subsample). Age, sex, and city of residence were compared between the accelerometer subsample and all 3214 nonrespondents, including those who did not respond to the initial questionnaire. In addition, multiple logistic regression analyses were used to compare the sociodemographic and lifestyle characteristics of the accelerometer subsample and the 722 respondents who participated in the questionnaire survey but not the accelerometry (questionnaire-only subsample).
As compared with all nonrespondents, the accelerometer subsample included significantly more women, middle-aged and older adults, and residents of specific cities. Multiple logistic regression analyses comparing the accelerometer and questionnaire-only subsamples revealed that participation in the accelerometry survey was greater among nonsmokers (odds ratio, 1.35; 95% confidence interval, 1.02-1.79) and persons who reported a habit of leisure walking (1.56, 1.21-2.01).
Sex, age, city of residence, smoking status, and leisure walking were associated with participation in accelerometry. This response pattern reveals potential selection bias in mail-based accelerometry studies.
调查对象和非调查对象的特征差异可能是选择偏差的一个原因。本研究旨在确定基于现场的加速度计调查中调查对象的社会人口学和生活方式特征。
一项横断面邮寄调查被发送给 4000 名成年人（50%为男性；年龄 20 至 69 岁），他们是从日本 4 个城市的居住地址登记处随机选择的。有 1508 名受访者（应答子样本）对初始问卷做出了回应。应答子样本中共有 786 名参与者同意佩戴加速度计 7 天（加速度计子样本）。比较了加速度计子样本与所有 3214 名未回复者（包括未回复初始问卷的人）的年龄、性别和居住城市。此外，还使用多变量逻辑回归分析比较了加速度计子样本和参与问卷调查但未参与加速度计测量（仅问卷子样本）的 722 名受访者的社会人口学和生活方式特征。
与所有未回复者相比，加速度计子样本中女性、中老年人和特定城市的居民明显更多。比较加速度计和仅问卷子样本的多变量逻辑回归分析表明，不吸烟者（比值比，1.35；95%置信区间，1.02-1.79）和有休闲步行习惯的人（1.56，1.21-2.01）更有可能参与加速度计测量。
性别、年龄、居住城市、吸烟状况和休闲步行与参与加速度计测量有关。这种应答模式揭示了基于邮件的加速度计研究中存在潜在的选择偏差。
