Background and objectives: This study was to clarify how the frequency of participation in a health class affected the reduction in sedentary behavior after two years, and whether decreases in sedentary behavior in elderly people who participated in a health class persisted two years after the end of an intervention. Materials and Methods: This study was longitudinal, and the results of a previous study conducted in 2017 were added to the findings of a different year. The participants were elderly health class members at a community dwelling in Japan who participated between 2016 and 2018. Of the 86 participants that were enrolled, the data of 80 were collected in 2016. A year later, in a 2017 follow-up, the number of participants was 80, and two years later, in a 2018 follow-up, there were 71 participants. Results: There was a significant difference with regards to the reduction of the sedentary behavior rate between two different groups (a health class participation rate of more than 75% and the other with less than 75%) two years later. However, no difference in sedentary behavior rate was found between the two groups (intervention group and control group) at a two-year follow-up, despite observing differences after one year. Conclusions: Continuous participation in a health class may help reduce sedentary behavior. After two years, "Active Guide" brochures and documents may not help in reducing sedentary behavior, despite seeing improvements after one year. Persistent social participation may have a more lasting effect than one-off interventions in reducing the sedentary behavior ratio.
Keywords: elderly people; health class; longitudinal study; sedentary behavior.