The change in lifestyle data during 9 years: the reliability and continuity of baseline health practices

Environ Health Prev Med The change in lifestyle data during 9 years: the reliability and continuity of baseline health practices Hanayo Koetaka 0 1 Yuko Ohno 0 1 Kanehisa Morimoto 0 1 0 K. Morimoto Environmental Health and Preventive Medicine, Osaka University Graduate School of Medicine , 2-2 Yamadaoka, Suita, Osaka 565-0871 , Japan 1 H. Koetaka Y. Ohno (&) Course of Health Science, Osaka University Graduate School of Medicine , 1-7 Yamadaoka, Suita, Osaka 565-0871 , Japan Objectives To reveal change patterns in self-reported lifestyle data for 9 years, and examine the characteristics of changes by type of lifestyle and ageing. Methods The authors used the lifestyle data of 7,080 male workers aged 20-59 who received checkups for 9 years. The proportions of change patterns during the 9 years were determined in seven health practices; smoking, eating breakfast, sleeping hours, working hours, physical exercise, eating nutritional balanced diets, and mental stress. Results Among seven health practices, the keep rate of good health practice was highest for the non-smoking (90.8 %), followed by eating breakfast (69.0 %);and the lowest was physical exercise (13.7 %). The keep rate of poor health practice was highest for smoking (73.8 %), followed by non-physical exercise (67.1 %). The lowest rate of multiple changes during 10 years was smoking (7.1 %); the highest was mental stress (68.5 %). Conclusions As for the life style on smoking and eating breakfast seemed to be stable, using the data obtained at a specific point in time wouldn't much affect the results. On the contrary, for other life styles, they showed poor continuity during 9 years, so it would be necessary to take into consideration the time point of data collection. Lifestyle; Health practices; Smoking; Change patterns; Continuity Introduction When using baseline information to estimate the relative risk of mortality or incidence of a disease, the baseline information usually remains fixed during the study period [ 1 ]. Attributes such as sex and age necessarily continue during the study period, but it is difficult to think that lifestyle data obtained at baseline will continue during the study period for all the subjects [ 1, 2 ]. In the long-term cohort studies, changes of baseline information will be subject to more change [ 1–3 ]. If exposure data obtained at baseline changed over time, the estimates of relative risk may be binned by inappropriate information of exposure [ 1, 2 ]. Analysis that takes into account changes in the baseline lifestyle data that occur during the study period is thus required. However, there has been little study to clarify the changes of baseline data [ 1, 2, 4 ]. In this study, we study lifestyle change patterns that easily occur during the study period. And we examine particular characteristics of the changes due to ageing and the type of lifestyle. Materials and methods Subjects In Japan, employees generally undergo regular annual checkups at their companies or at company-designated clinics. In this study we used checkup data belonging to the Japanese Foundation that performed the checkups under contract from companies. Records of 7,080 male workers aged 20–59 who received checkups at the Foundation continually for 9 years from 1995 to 2004 were used. We received electronic data that cannot specify those who took a checkup from this Foundation. This study was approved by the ethical committee of the course of Health Science, Osaka University Graduate School of Medicine. Lifestyles The lifestyle factors were assessed by using a self-administered questionnaire that asked about eight health practices, which has been used by Morimoto et al. [ 5–9 ]. Subjects answered eight questions shown in Table 1 by ‘‘true’’ or ‘‘false’’. In this study, we analyzed changes that occurred in a 9-year period for seven health practices (smoking, physical exercise, sleeping hours, mental stress, hours of work, eating breakfast, and eating nutritional balanced diets) excluding alcohol consumption. The rate of subjects with a poor health practice of alcohol consumption was less than 10 %. When classifying by the pattern of change, the number of subjects for the each category became too low. So alcohol consumption was excluded from this analysis. Analysis Subjects were separated by their age in 1995 into groups of 10 years each. For each age group of 10 years, we analyzed change patterns for the seven health practices using the following procedure. First, we divided the subjects into two groups, the good health practice group and the poor health practice group, based on their health practice characteristics in 1995. Next, each group was further divided into three groups: the keep health practice group, which maintained their habits during the 10-year period; the deteriorate/improve health practice group, whose habits either worsened or improved; and the multiple changes group, whose habits fluctuated back and forth (...truncated)