A prevalence study on mild cognitive impairment among the elderly populations of Mongolian and Han nationalities in a pastoral area of Inner Mongolia

Abstract

To understand the epidemiological characteristics and distribution of mild cognitive impairment (MCI) in elderly populations from Mongolian and Han nationalities living in the pastoral areas of Inner Mongolia Autonomous Region of China. According to the MCI clinical diagnostic criteria from Diagnostic and Statistical Manual of Mental Disorders 4th revised edition (DSM-IV) by American Psychiatric Association, the individuals under study were at the age of 55 or over, with Mongolian or Han ethnicities and living in the pastoral area of Inner Mongolia. The crude MCI morbidity rates of Mongolian and Han of the study populations in the pastoral area of Inner Mongolia Autonomous Region of China was 19.48% (1782/9146) and the standardization morbidity was 18.98%. The crude MCI morbidity rates of both Mongolian and Han ethnicities were 17.46% (the standardization morbidity was 16.99%) and 20.60% (the standardization morbidity was 19.98%), respectively. There showed a significant positive correlation between the crude morbidities and age, also significantly increasing with the latter. In the Mongolian population, the morbidity increased from 12.17% at the age 55-59 to 27.78% at 85 while in the Han population, the morbidity increased from 15.50% at the age 55-59 to 23.53% at 85. In both the populations of Mongolian and Han, there was a statistically difference found between the morbidities of MCI (χ2=13.229, P=0.000). The morbidity was higher in Hans than in the Mongolians. However, there was no statistically significant difference noticed between the morbidities of MCI in the Mongolian males and females (χ2=2.376, P=0.123). There was statistically significant difference found between the morbidities of MCI in the Han males and females, with females having higher risk than males (χ2=24.470, P=0.000). The morbidity of MCI in the elderly Mongolian and Han populations from the pastoral area of Inner Mongolia Autonomous Region of China was considered to be quite high and correlated to age and gender.