[Change of cognitive function and associated factors among the rural elderly: a 5-year follow-up study].

Objectives: This prospective population-based cohort study was conducted to evaluate the risk factors of cognitive impairment and the degree of cognitive function change through a 5-year follow-up.

Methods: The baseline and follow-up surveys were conducted in 1998 and 2003, respectively. Among 176 subjects who had normal cognitive function in the baseline study, 136 were followed up for 5 years. The cognitive function was investigated using the Korean version of the Mini-Mental State Examination (MMSE-K). The collected data were analyzed using SPSS and Stata.

Results: Of the 136 subjects analyzed, 25 (18.4%) were cognitively impaired. Old age and low social support in the baseline survey were risk factors for cognitive impairment after 5 years. In the generalized estimating equation for 128 subjects except severe cognitive impairment about the contributing factors of cognitive function change, the interval of 5 years decreased MMSE-K score by 1.02 and the cognitive function was adversely affected with increasing age, decreasing education and decreasing social support.

Conclusions: Although the study population was small, it was considered that the study results can be used to develop a community-based prevention system for cognitive impairment.