Iwasaki Motoki, Otani Tetsuya, Yamamoto Seiichiro, Inoue Manami, Hanaoka Tomoyuki, Sobue Tomotaka, Tsugane Shoichiro
Epidemiology and Biostatistics Division, National Cancer Center Research Institute East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577, Japan.
J Epidemiol. 2003 Jul;13(4):216-25. doi: 10.2188/jea.13.216.
Although epidemiologic studies including the Japan Public Health Center-based Prospective Study on Cancer and Cardiovascular Disease (JPHC study) have frequently used the basic health examination participants as study subjects, their background characteristics have rarely been investigated. The aim of this study is to clarify the background characteristics of participants and to discuss their impact on epidemiologic studies.
Subjects were 43,140 (Cohort I) and 34,892 (Cohort II) respondents aged 40-59 years who completed a self-administered questionnaire in 1990 or 1993-94 by the JPHC Study. Respondents whose data of the basic health examination were also available were defined as participants. We compared their sociodemographic factors, personal medical history, and lifestyle-related factors with those of non-participants.
Participants tended to be older and less educated. They were more likely to engage in agriculture, forestry and fisheries or to be self-employed persons, or homemakers. Male participants smoked less and were more likely to drink alcohol beverage moderately. Female participants smoked and drank less but tended to participate more in sports and physical exercise in their leisure time. Both male and female participants tended to eat fruits and green vegetables more often than non-participants. In short, participants had a different socioeconomic status from non-participants and a favorable lifestyle profile, especially among women. These findings were principally consistent between the two cohorts.
These differences between participants and non-participants in the basic health examination might cause a selection bias that limits the application of the results to only participants in the basic health examination.
尽管包括日本公共卫生中心癌症与心血管疾病前瞻性研究（JPHC研究）在内的流行病学研究经常将基础健康检查参与者作为研究对象，但很少对他们的背景特征进行调查。本研究的目的是阐明参与者的背景特征，并讨论其对流行病学研究的影响。
研究对象为43140名（队列I）和34892名（队列II）年龄在40至59岁之间的受访者，他们在1990年或1993 - 1994年完成了JPHC研究的自填式问卷。基础健康检查数据也可用的受访者被定义为参与者。我们将他们的社会人口学因素、个人病史和生活方式相关因素与非参与者进行了比较。
参与者往往年龄较大且受教育程度较低。他们更有可能从事农业、林业和渔业，或为个体经营者或家庭主妇。男性参与者吸烟较少，更有可能适度饮酒。女性参与者吸烟和饮酒较少，但在休闲时间更倾向于参加体育和身体锻炼。男性和女性参与者都比非参与者更经常食用水果和绿色蔬菜。简而言之，参与者与非参与者的社会经济地位不同，且生活方式良好，尤其是在女性中。这些发现在两个队列之间基本一致。
基础健康检查中参与者与非参与者之间的这些差异可能会导致选择偏倚，从而限制研究结果仅适用于基础健康检查的参与者。
