Associations between community social capital and posttraumatic growth among older survivors 11 years after a natural disaster.

We prospectively examined whether community-level social capital plays a significant role in developing posttraumatic growth (PTG) among older survivors of the 2011 Japan Earthquake and Tsunami. The baseline survey was conducted 7 months before the disaster among residents of a city located 80 km west of the earthquake epicenter. The survey inquired about participants' health status and social capital (informal socializing and social participation, as well as social cohesion). Approximately 2.5 years after the disaster, we surveyed older survivors to assess their disaster experiences. A follow-up survey in 2022 inquired about PTG in the 11 years following experiences of the disaster (n = 1819). Multilevel linear regression analysis showed that predisaster community-level informal socializing and social participation was associated with higher PTG scores (coefficient = 0.25; 95% CI, 0.02-0.47). In cross-classified multilevel regression, maintenance of higher community-level informal socializing and social participation during the postdisaster period was associated with higher scores of PTG (coefficient = 0.22; 95% CI, 0.07-0.37). Predisaster community-level informal socializing and social participation were associated with higher PTG scores among older survivors. Interventions encouraging social interactions among neighbors may be effective in promoting PTG of survivors after natural disasters.