Recently, overseas studies have focused on the interaction effects between accessibility to open spaces and individual-level poverty (e.g., income) as a factor of social inequalities in health. These studies have reported that people with a higher degree of individual-level poverty are more likely to be vulnerable to negative health effects due to inferior accessibility to open spaces, which may contribute to social inequalities in health. However, few studies have focused on the interaction effect between accessibility to open spaces and area-level poverty. We hypothesized that individuals living in areas with a high degree of area-level poverty are more likely to experience negative health effects due to inferior perceived accessibility to open spaces. We conducted the following study using data obtained through a mailed questionnaire survey in the Densely Inhabited District of Osaka Prefecture, Japan. Initially, we tested for health disparities related to subjective health, subjective well-being, and frequency of exercise. Next, we examined which of the above-mentioned interaction effects had a more significant impact on health. Our results showed health disparities in subjective health and subjective well-being. The interaction effect between perceived accessibility and area-level poverty had a more significant health impact than the other interaction effects on subjective health. None of the two interaction effects had any significant effects on subjective well-being and frequency of exercise. Policy implications for reducing social inequalities in health may include measures to improve the perceived accessibility to open spaces of residents in areas with a high degree of area-level poverty.
