Abstract
BACKGROUND: It is of considerable public health importance to prevent or delay the progression of mild cognitive impairment (MCI) to more severely impaired cognitive states. This study examines the risk of progression from mild to severe cognitive impairment in relation to engagement in social activities while mildly impaired and the concurrence of subsequent change in engagement with MCI progression. METHODS: Participants were 816 older adults with cognitively defined MCI (mean age 78.0 (standard deviation or SD = 7.4) years) from the Monongahela-Youghiogheny Healthy Aging Team (MYHAT) Study--a prospective cohort study of MCI in the community. Over three years of follow-up, 78 individuals progressed from MCI to severe cognitive impairment, while 738 did not progress. Risk of progression was estimated using discrete time survival analyses. The main predictors were standardized composite measures of the variety and frequency of engagement in social activities. RESULTS: Lower risk of progression from mild to severe cognitive impairment was associated with both a greater level of frequency of engagement in social activities while mildly impaired (OR = 0.72, 95% CI: 0.55-0.93, p = 0.01) and also with a slower rate of decline in the variety of activities over time (OR = 0.01, 95% CI: <0.001-0.38, p = 0.02). CONCLUSIONS: Greater engagement in social activities may potentially be beneficial for preventing or delaying further cognitive decline among older adults with MCI. Alternatively, lesser engagement in social activities may be a marker of impending cognitive decline in MCI.