Fig. 1

Flow chart of study participants. We excluded 6090 participants under 65 years in age from the first wave to ensure that we analyzed only individuals 65 years or older (n = 4164). Additionally, we excluded participants with cognitive impairment (Korean Mini-Mental State Examination [K-MMSE] score under 24) at the first wave (n = 2198). We also excluded participants who did not complete the questions on the independent variables of interest (e.g., socioeconomic status, social activity participation, and health-related variables) or the dependent variable (K-MMSE). To analyze changes in variables over time, we excluded participants who did not participate in more than two follow-up surveys. Ultimately, 1806 people were analyzed in 2008, 1585 in 2010, 1472 in 2012, 1354 in 2014, and 1222 in 2016