An epidemiological study of dementia among the habitants of eastern Uttar Pradesh, India.

UNLABELLED: Dementia is one of the most serious health problems of the elderly and their caregivers.
OBJECTIVE: The objective of this study was to estimate the prevalence of dementia in the community, its sociodemographic and behavioral associates to determine the risk factors among resident of two districts of eastern Uttar Pradesh, India.
MATERIALS AND METHODS: This study was based on 2890 subjects aged 50 years and above, residing in rural areas of Mirzapur and urban areas of the Varanasi district of eastern Uttar Pradesh, India. Efforts were made to identify the subjects of age 50 years and above using cluster sampling. The Hindi Mental State Examination was used as the instrument tool to determine the score and a cut-off score of ≤23 was considered as the presence of dementia among the identified subjects.
RESULTS: The overall prevalence of dementia was found to be 5.1%. This percentage was increasing with age and decreasing with educational level. Among females, the prevalence of dementia was observed (7.2%) to be double than that in males (3.8%). Widows/widowers/unmarried had a double prevalence (9.3%) as compared with married (4.3%) people. The age, gender, marital status, education, occupation, number of family members in the household and liquor addiction were found to be significantly associated with dementia. The relative risk for the above-mentioned variables was found to be more than 1.

Introduction

Dementia is an acquired syndrome produced by malfunction of the brain in the elderly, and is characterized by persistent impairment in multiple areas of intellectual function. This disorder causes extremely bad consequences for patients, families, societies and nations. The prevalence of dementia is increasing with aging among the world population. It is a major public health problem worldwide among the elderly, particularly in developing countries where the aging population is growing most rapidly.

The prevalence of dementia among rural habitants of age 60 years and above was 2.7%,[1] and it was reported to be 3.6% in the urban population.[2] Shaji et al. (1996)[3] have reported this Figure as 3.4% in the rural community of Kerala. Among the population of age 55 years and above of a rural community in Northern India, the prevalence rate of 8.4 per 1000 was reported.[4] Considering the magnitude of this problem, it is essential to focus our attention on the burden of this disease in the elderly population, which can make a significant impact on our society.

Objectives

The objectives of this study were: (1) to determine the prevalence of dementia, (2) to ascertain the association of dementia with sociodemographic, behavioral and comorbidity variables and (3) to estimate the effect of risk factors and establish a 95% confidence interval for each study variable.

Materials and Methods

This study was based on 2890 consenting individuals aged 50 years and above from the rural community of Pahari Tehsil of Mirzapur district [Figure 1] Villages taken under the study are highlighted and urban areas of Bhelupur ward in Varanasi district of eastern Uttar Pradesh, India. The complete enumeration was performed from randomly selected clusters of these areas and data were collected through a door to door survey on a predesigned and pretested schedule method by using a cross-sectional study design.

Figure 1

Map of the rural area of Mirzapur district

Assessment tool

The most common language that the subjects could understand was Hindi and, therefore, the Hindi version of the Mini Mental State Examination (MMSE) was used and the standard followed by Ganguly et al. (1995)[5] was maintained. This Hindi Mental State Examination (HMSE) consists of 22 items that test the different components of intellectual capability. The examination covers several areas of cognitive functioning, such as orientation to time and space, attention and concentration, recognition of objects, language function, both comprehensive and expressive speech, motor functioning and praxis. It is relatively simple to administer and provides a quick, brief index of the subject's current level of mental functioning. It is a modified version of the MMSE.[6] Here, a cut-off score of ≤23 was taken to screen the dementia cases, with a sensitivity of 88%, specificity of 82% and with an interrater reliability coefficient of 0.9 as per that reported by Shaji[3] et al.

Study design

By applying the cross-sectional design, the data were collected in two phases on the same day. During the first phase, all the subjects were thoroughly interviewed by a psychologist and the background information like age, gender, education, marital status, dietary habits, number of family members, number of earning family members, addiction (tobacco and alcohol) and associated morbidities were noted. In the second phase, the HMSE was administered to determine the cognitive decline.

Statistical analysis

The data were entered in the MS Excel software after completion of data collection and scrutiny. The qualitative data was presented in the form of number and percentage. The significant association of dementia with sociodemographic, behavioral and comorbidity variables was tested by the X2 test at a 5% level of significance and at the two-tailed test. The relative risk (RR) and 95% CI were calculated for each study variable. The statistical calculation was performed using the Statistical Package of Social Sciences (SPSS), version 16.0.

Results

The result of this study was based on 2890 subjects, consisting of 72.6% from rural and 27.4% from urban areas. The overall prevalence of dementia was observed to be 5.1%, with 5.5% among rural and 3.8% among urban inhabitants, but this difference was statistically insignificant [Table 1]. The value of RR shows a 1.46-times higher risk for rural areas, but this was insignificant. Further analysis has been performed on all subjects. The distribution of the subjects in the age groups 50-59, 60-69, 70-79 and 80 years and above was 51.4, 32.5, 13.3 and 2.8%, with a prevalence of dementia of 2.6, 6.9, 8.1 and 15%, respectively, which shows that the prevalence increases with age (P = 0.000, Table 1). The percentage gender distribution was 63.1 for males and 36.9 for females, and the prevalence of dementia in males and females was 3.8% and 7.2%, respectively, i.e. the prevalence was approximately double in females as compared with that in males (P = 0.000, Table 1). The RR for females was 1.91, with a 95% CI of 1.39-2.62. 15.3% of the subjects were widows/widower/unmarried and, among them, 9.3% were suffering from dementia as compared with 4.3% among the married subjects, i.e. approximately double in widows/widower/unmarried (P = 0.000, Table 1). The RR for widows/widower/unmarried was 2.16, with a 95% CI of 1.52-3.04.

Table 1

Association of sociodemographic variables with dementia

A continuous pattern of decrease in the prevalence of dementia was observed with increase in the educational level. The prevalence of dementia in the uneducated was 12.6%, which decreased to a significant level of 3.4% for subjects educated up to class 5th, then further reduced to 2.8% for classes 6th to 9th and 2.2% for high school and onwards (P = 0.000, Table 2). The prevalence in the unemployed subjects was 7.1% as compared with 4.6% in the self-employed, 3.9% in retired subjects and 2.4% in employed subjects (P = 0.001, Table 2). The total number of earning members in the family had no significant association with the prevalence (P = 0.15, Table 2). The total number of members in the family had a significant association with the prevalence (P = 0.02, Table 2), as the subjects from family size of 16 and more had the least prevalence of 2.4% whereas subjects living with family members less than 5, 6-7, 8-10 and 11-15 had a prevalence of 4.4, 3.9, 6.6 and 6.8%, respectively.

Table 2

Association of socioeconomic variables with dementia

The type of diet had no significant association (P = 0.163), as Table 3 shows that the prevalence of dementia among vegetarians was 5.6% as compared with 4.4% among nonvegetarians. The RR for vegetarians was 1.26, but this was insignificant. Tobacco chewing and smoking had no significant association (P = 0.133 and 0.34, respectively; Table 3). However the use of liquor had some significance (P = 0.043). Subjects taking liquor had a prevalence of 1.4%, and those who claimed not to take liquor had a prevalence of 5.2% [Table 3]. The proportion of subjects with comorbidities of hypertension, diabetes and ischemic heart disease was 29.1, 12.0 and 0.4%, with prevalence of dementia of 6.2, 6.2 and 0%, respectively. These diseases had no significant association (P = 0.08, 0.29 and 0.44, respectively) [Table 3].

Table 3

Association of personal habit and co morbidity variables with dementia

Discussion

The extensive studies from developed countries have provided a range of prevalence between 3.8 and 10% in the age group above 65 years of age.[78] Very few studies are available from developing countries. Several community-based urban and rural studies have been reported on dementia from different parts of India, with a varying range of prevalence from 1.02% to 4.86% in the age groups 55-65 years and above.[1-49-12] The findings of our study show that the prevalence of dementia was 5.1%, which was higher in comparison with other Indian studies, but is consistent with other studies of Asian and western countries. Raina et al.[13] reported a higher prevalence of dementia of 6.5% among the Kashmiri migrants of age groups 65 years and above. It was ranging between 8 and 15% in the age group of 70 years and above. In our study, the prevalence in females was approximately double than that in males, which is comparable with other studies.[13] This may be due to better care given to males as compared with females, as the study area was predominantly a male-dominated society. A large part of the developing countries is still rural. The prevalence rates obtained in this study for rural and urban populations were 5.5 and 3.8%, respectively. Raj Kumar and Kumar[1] reported a higher prevalence of dementia in the rural community than in an urban setting, which support the results of our study. Shibayama[14] also found higher prevalence rates of dementia in rural areas of Japan compared with that in urban areas. The factors contributing to this difference are probably, different life styles and health awareness. The marital status also had a significant impact on the prevalence of dementia. Widows/widower/unmarried showed an almost double prevalence as compared with married subjects. This may be due to a better social life in married subjects, although this has not been reported in other studies and needs more evaluation. The prevalence rates among uneducated and educated up to class 5th were 12.6 and 3.4% respectively in our study. This shows that education, even of primary level, may reduce the prevalence of dementia at a later age. In a pilot study conducted by Shaji[10] with a Malayalam adaptation of the MMSE, there was no significant difference in the total MMSE scores between the literate and the illiterate. Mathuranath et al.[12] also reported the association of low education with dementia. In our study, we also tried to establish an association between dementia and occupation. The prevalence of dementia in unemployed subjects was 7.1% in comparison with 2.4% in the employed. This needs further evaluation. Similarly, an association between types of family and status of dementia showed a lower prevalence in joint families. This is possibly because of a healthier atmosphere and number of helping members in the family, which strengthens the relevance of Indian culture in the study. This has not been reported in any other study from developing or developed nations. Diet, tobacco chewing, smoking and concomitant diseases had no significant association with dementia. However, the prevalence was found to be less in people who consumed alcohol in our study. This may due to lesser people confessing intake of alcohol.

Conclusions

To conclude, the prevalence rate of dementia is higher in our study than that reported in India earlier, except a report from Raina et al.[13] on Kashmiri migrants. We tried to relate various parameters like gender, marital status, occupation, education, employment, size of family and residential status. Diet, tobacco chewing, smoking, liquor intake and concomitant diseases had no significant association with dementia. The global prevalence of dementia gives the population of demented people in India as 1.5 million in 2001, and says it is set to increase by more than 300% by 2040 (may reach six million).[8] Early screening of dementia through the assessment tool of HMSE will be helpful in giving a better quality of life, providing guidelines to care providers as well as launching national health programmes for such types of diseases.