Objectives　Personal income affects dental status in older people. However, the impact of income inequality on dental status at the community level (junior high school district) is unclear. The purpose of this study was to examine the association between dental status and community level income inequity after adjust for individual socio-economic status in Japanese older adults, and to verify the relative income hypothesis, also known as the Wilkinson hypothesis.

Methods　We used data from the Japan Gerontological Evaluation Study (JAGES) conducted in Niigata city. JAGES is a postal survey of functionally independent adults aged 65 years or older. We enrolled 4,983 respondents (response rate 62.3%) and used data on 3,980 of them after excluding incomplete data. We evaluated health condition and socio-economic status using questionnaires. The Gini coefficient, as an indicator of income inequality, was calculated by junior high school district (57 districts) based on the data from the questionnaire. Additionally, the Pearson's coefficient of correlation was calculated to evaluate the association between the mean number of remaining teeth and the community level Gini coefficient. Then we evaluated the mean number of remaining teeth among the groups stratified by the Gini coefficient conditions. Next, we conducted a multilevel analysis using an ordinal logistic regression model. The number of remaining teeth was set as the dependent variable, while sex, age, household size, education, smoking status, diabetes treatment, current living conditions, and equivalent income were used as independent variables at the individual level. The Gini coefficient and average equivalent income in the junior high school district were used as independent variables at the community level.

Results　The Pearson's correlation coefficient for the relationship between the Gini coefficient and the mean number of remaining teeth in the junior high school district was −0.44 (P<0.01). Wider income disparity area (Gini coefficient≧0.35) revealed a significantly small number of remaining teeth (P<0.001). The multilevel analysis showed that a higher Gini coefficient and a lower average equivalent income at the community level were significantly associated with a lower number of remaining teeth, and with educational attainment, smoking status, current living conditions, and equivalent income at the individual level, after adjusting for sex and age. On the other hand, educational attainment at the individual level, and average equivalent income at the community level were not significant factors after adjusting for all individual level variables.

Conclusion　This study showed that, in addition to individual socio-economic status, income inequality at the community level was significantly associated with number of remaining teeth in Japanese older adults. Although the precise mechanism of this association is still unclear, our result supports the relative income hypothesis.

Objectives　Promoting physical activity is a key public health issue. Incentive programs have attracted attention as a technique for promoting physical activity. For the use of effective incentives, there is a need to clarify the most effective incentive program conditions for the promotion of physical activity. Therefore, the present study used the conjoint analysis to examine the effective incentive program conditions for strengthening the motivation to increase physical activity.

Methods　Data on 1,998 subjects (aged 40-74) were analyzed. The main variables in this study were physical activity (IPAQ-Short Form) and the strengthening of motivation to increase physical activity. The incentive programs that were implemented, comprised four factors: 1) cash equivalents (1,000 yen, 2,000 yen, and 3,000 yen); 2) duration between increase in physical activity and receipt of the incentive (1, 2, or 3 months); 3) method to record the physical activity (recording sheet, recording website, and automatic pedometer recording); and 4) lottery (yes or no). Eleven incentive programs were created, which was the minimum number required for comparison of these factors and levels. The average importance of each of the four factors was calculated to compare their contributions to the strengthening of the motivation to increase physical activity. The utility of each level was also calculated to compare their contributions to the strengthening of motivation. All statistics were stratified by age (≤65 years and 65+ years) and physical activity (<150 min/week, 150+ min/week) for additional analysis.

Results　Cash incentives and the lottery ranked equally on average importance, followed by duration and recording methods. Utility was higher for each factor, as follows: 1) more valuable cash incentives, 2) shorter duration, 3) automatic pedometer recording, and 4) no lottery. There was no notable difference in the average importance and utility of age and physical activity.

Conclusions　The results of this study suggest that no lottery and more valuable incentives were important for improving the effectiveness of incentive programs in increasing physical activity. Moreover, these two factors would be important regardless of age and physical activity levels. Further intervention studies on incentive programs for increasing physical activity considering the present results are needed.

Objective　To evaluate the effectiveness of a training program designed to address the following three challenges facing health promotion volunteers: lack of new volunteers, short tenure of volunteering, and failure to build a collaborative relationship with other civic organizations.

Methods　Thirty-eight volunteer leaders representing 36 school districts (one from each district and two additional leaders) from southern parts of Shiga Prefecture participated in the training program. Four training sessions were conducted between July 2012 and January 2013. Each session lasted for 2 hours. The program included a lecture, group work, and role playing, all of which centered on the challenges experienced by the volunteers and possible solutions. Those who participated constituted the “training group,” and other volunteers in the same area of Shiga, who did not take part in the program, made up the “non-training group.” A third, control group consisted of health promotion volunteers based in City A, located outside the areas where the training occurred. To compare the three groups, we collected data before and after the training. The main evaluation index comprised the following three survey items: having confidence in recruiting new volunteers, having confidence in overcoming the difficulties or discouragement to continue to volunteer, and having confidence in explaining their activities to other local organizations to earn their cooperation. These questions were asked in a self-administered questionnaire using a 6-point Likert scale (1: strongly disagree, 6: strongly agree).

Results　The data were compared among the training group (28 out of the 38 participants completed the survey), non-training group (n=293), and control group (n=107). On the question about recruiting new volunteers, the training group's mean score increased from 2.9 (standard deviation (SD)=1.3) to 3.3 (SD=1.0) following the training, and the improvement relative to the other two groups was statistically significant (P=0.008 for training vs. non-training, P<0.001 for training vs. control). On the question related to overcoming challenges and continuing volunteering, the training group's mean score went up from 3.3 (SD=1.1) to 3.5 (SD=0.9). The change was statistically significant compared to the non-training group (P=0.033), but not compared to the control group (P=0.401). No statistically significant change was found for the cooperation variable.

Conclusion　Overall, this training program appears to be effective in addressing the challenges that health promotion volunteer organizations face.

Nihon Koshu Eisei Zasshi(JAPANESE JOURNAL OF PUBLIC HEALTH), Vol. 63 (2016) No. 11 p. 664-674: p668(Table 2)