By dividing the participants recruited for this study into two groups, significant differences were observed for the proportion of widowed people rather than the proportion of those the proportion of those with high levels of education. Consistent with previous studies in the United States and South Korea [23,24], our finding suggests a higher risk of severe cognitive impairment among unmarried elderly persons as opposed to those who are married. In our study, only one of three most common unmarried statuses (single, divorced, and widowed) was investigated since our survey indicated that single and divorced elderly persons were rare compared to those who were widowed. Brenowitz and his colleagues found that only the widowed, rather than the single or divorced, held a significant risk for mild cognitive impairment, where the incidence rates for mild cognitive impairment among older married individuals were used as a baseline . Therefore, it is reasonable to suggest that widowed older persons should be investigated separately rather than in conjunction with single or divorced elderly people. Despite women have longer life expectancies than men , we found that high-age elderly men and women had similar high widowhood rates. This finding suggests that it is more difficult to continue marriage at an advanced age than to extend life itself for both long-lived men and women. Therefore, marital status is more important for their cognitive ability maintenance than for the younger elderly persons.
For elderly persons with mild cognitive impairment, living in a professional pension institution is not as cost-effective compared to living at home . But through dialogue, we learned that avoiding becoming a burden to their children, rather than economic efficiency, was the main reason many elderly participants chose institutional care. Concern over cognitive decline is the leading reason why older people choose institutional care . Our observation indicates that cognitive functioning among elderly people living in professional pension institutions was generally poor. This finding is consistent with the assertions of Werner and Segel-Karpas, where concerns over dementia may be due to signs of dementia . Other possible explanations for this is that a shift from familiar surroundings to a new residence in an unfamiliar place might have a negative impact on cognitive functioning . Subsequently, weak interpersonal relationships established in institutions can hardly replace the strong emotional support that comes from marriage. The substitution of strong interpersonal relationship with multiple weak interpersonal relationships has been proven harmful to cognitive functioning . Nevertheless, our results suggest that maintaining married status in old age is still beneficial to maintaining cognition compared with being widowed, even if there are deficiencies in professional pension institutions.
Results of a recent study show that cognitive decline is not inevitable among at-risk elderly persons if continuous lifestyle interventions can be adopted . Compared with other high-age people, married high-age participants with high levels of education were identified as being protective against severe cognitive impairment; this finding was consistent with previous studies [31,32]. Segmentation of the participants implies that married low-age elderly people with high levels of education have the lowest risk of suffering from severe cognitive impairment when they are over 80 years old. Our results suggest that in this subpopulation, the demographical indicators of education and marriage demonstrate a synergistic prevention pattern against severe cognitive impairment. However, it should be noted that such a lower risk was only the result of comparison with the high-age group. Compared with other people in the low-age group, these people did not show a lower rate of severe cognitive impairment.
There are some limitations to this study. First, the sample size of this study is small and we only focused on the elderly people living in professional pension institutions, and we did not investigate the elderly persons living at home. Therefore, the main conclusion identifying an age-related education-marriage synergetic relationship should be considered with caution and is in needs of further validation by larger-scale panel studies. Second, clinical diagnoses of severe cognitive impairment were not used in the study. Relying solely on the MMSE measures may possibly result in the misclassification of research participants. Third, because this is a cross-sectional study, it is difficult to determine the exact role of education-marriage synergy on delaying cognitive decline in elderly people from the perspective of individualization. Fourth, additional factors related to cognitive decline including cardiovascular and cerebrovascular diseases, tobacco and alcohol use, and life style were not evaluated or used for data segmentation in this study.
This cross-sectional study reveals that education alone does not sufficiently address the complexity of protective factors against age-related cognitive decline. Maintaining the integrity of marriage is also necessary for ensuring behavioral independence in the late stage of older life. This age-related synergy between education and marriage against cognitive decline suggests that a stable and strong interpersonal relationship is important for the growing subpopulation of long-lived elderly people with high levels of education. The benefits of marriage become more apparent as people get older. Nowadays, an increasing number of well-educated women are choosing to live independently rather than marry over considerations of economic independence. This may disrupt the collaborative impact between education and marriage. Further comparative studies are needed to investigate the potential impact of this trend on senile dementia.