Prevalence of Cognitive impairment among community dwelling rural elderly of Bangalore, India

Introduction

We live in an aging world. India is a greying population as the mortality and fertility rates are on a decline. The elderly have been defined as those above the age of 60yrs. Old age has been categorized into young old (60- 69 yrs), old old (70- 79 yrs) and oldest old (>80yrs).¹ Sharp decline in fertility rates combined with the socio economic growth in many developing countries will lead to a further increase in the population of the elderly in future.² Elderly proportion in India according to 2011 census is 8.1% and is expected to rise to 17% by the year 2025.^3,4 According to the World Health Organization (WHO), India’s aged population is the second largest in the world.

Geriatrics is the branch of medicine that focuses on health care of the elderly. Geriatric medical care differs from usual medical care in shifting the focus to preservation of function and improving the quality of life rather than treating and curing specific diseases. Hence geriatric medicine focuses on restoration of function, on care rather than cure and on maintenance of independent living.⁵ The special features of Indian elderly population which is a challenge are a majority (80%) of them being in the rural areas, large percentage (30%) being in below poverty line, feminization of the elderly population, and increase in the number of the oldest age group (≥ 80 years).^4,6 Functional Assessment is a comprehensive evaluation of the physical and cognitive abilities required to maintain independence. The benefits of functional assessment are increased diagnostic accuracy, improved functional status, improved affect and cognition, improved survival, and decreased hospital use and medication costs. The benefits of geriatric functional assessment are increased diagnostic accuracy, improved functional status, improved affect and cognition, improved survival, and decreased hospital use and medication costs.⁷ As our population ages, impaired cognition is a growing problem. The Mini Mental Status Examination is validated tool which is used worldwide for assessing cognition among the elderly. The Hindi Mental Status Examination (HMSE) is an Indianized version of Mini-Mental State Examination.⁸ Studies done among elderly have shown the prevalence of dementia as being between 10–20%.^9,10 But researchers in India using HMSE have found much less prevalence of dementia among elderly, of around 3- 6%.^11,12 Patients with dementia are at higher risk for needing home care services and eventually nursing home placement. Delirium is also more common in patients with dementia and carries with it increased risk of morbidity and mortality. Hence a study to assess cognitive impairment among elderly in rural areas of Bangalore was undertaken.

Materials and Methods

This was a cross-sectional study, carried out at two villages of Bangalore District, Karnataka, South India. All persons above the age of 60 years resident in these two villages were included in the study. Elderly persons not found at their places of residence even after three attempts to contact and moribund bedridden elderly were excluded from study. A house-to-house survey was conducted to identify elderly persons. Informed consent was taken, and a pretested questionnaire was administered by the interviewer to the subjects. Demographic details, educational status, living arrangements, occupation, financial dependence, habits were collected. ‘Standard of Living Index’ was used to classify socioeconomic status of the families as low, middle, and high socioeconomic class. Financial dependence was assessed by asking whether the elderly person was financially dependent on family members, either partially or completely.

Cognitive impairment was assessed using the Hindi Mini-Mental Status Examination (HMSE) scale, the Indian version of the Mini-Mental State Examination, which is suitable for cognitive screening of the largely illiterate rural elderly population in India.¹³ Questions on orientation to time and place, immediate recall, short-term verbal memory, calculation, language, and construct ability was assessed cognitive impairment. It is a 31-point scale, hence was scored according accordingly to each question. A score of 20 or less was considered as cognitive impairment.

HMSE which is a widely used, well-validated screening tool for cognitive impairment. The items cover several areas of cognitive functioning such as orientation to time and place, memory, attention and concentration, recognition of objects, language function, both comprehension 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 functioning. It is a 31-point scale and a score of 20 or less generally suggests dementia. A score of less than 24 may indicate dementia in some welleducated persons. The test is useful for identifying patients with no impairments and with more severe dysfunction. The test is less sensitive for patients with a moderate degree of dementia. Serial testing may be of value to demonstrate a decline in cognitive function in borderline cases. Factors unrelated to dementia that may lower test scores include educational level, depression, mental retardation, and delirium Basic functional assessment for mobility, ability to use upper limb, presence of depression and urinary incontinence was done.

Results

50% of the elderly were young old (60 – 69 yrs), 30.2% elderly were old old (70 – 79 yrs) and 19.8% of the elderly were oldest old (80 yrs and above). Similar proportions were seen in males and females.

Assessed using Standard of Living Index.

64.4% of the elderly persons belonged to high Socio-economic status and 10.8% of the elderly persons belonged to low socio economic status.

74.3% of the elderly persons were illiterate, 2.7% had studied up to high school and one elderly person had completed Graduation. A significantly greater proportion of females were illiterate compared to males, when illiteracy (“illiterate”) was compared with any level of education (Chi square value = 33.97, df = 1, p<0.001).

56.7% of elders were staying with their spouse, 37.4% were widowed, 3.6% were separated and 2.3% were unmarried. Significantly higher number of the elderly males (83.7%) were married and living with their spouse compared to elderly females(35.5%), when elderly who were married and living with their spouse were compared with the rest (Chi square value = 51.79, df = 1, p<0.001). Significantly higher number of elderly females were widows (56.5%) compared to elderly males (13.3%), when widowed elderly were compared with the rest (Chi square value = 14.76, df = 1, p<0.001).

59.5% of the elderly were completely dependent on others for money. 22.1% of the elderly were independent financially. 18.5% of the elderly were partially dependent on others for money. More elderly females were financially dependent (72.6%) on others compared to elderly males, when financially dependent elders were compared to financially independent elders (Chi square value = 18.9, df = 1, p<0.001).

95.5% of the elderly did not have any cognitive impairment and 4.5% of the elderly had cognitive impairment. Cognitive impairment was significantly more among the elderly females compared to elderly males (Chi square value = 4.95, df = 1, fishers exact < 0.05) 

There was no significant difference between age groups with respect to cognitive impairment.

Discussion

The number of elderly persons enumerated in the two villages was 257, comprising 12.2% of the total population. This is higher than 7.7%, the national average for rural India.³ Most of the elderly (50%) belonged to the young old age group. Most of the elderly especially elderly females did not know their exact age. Estimates were done based on their birth before or after Indian independence, age of the first child; age at marriage and for females, age of menopause. A possible reason for higher estimation of the proportion of elders could also be because of the overestimation of the age by the elderly as mentioned in other study.¹⁴

Of these elderly persons 126(11.5%) were males and 131(13%) were females. According to Census of India 2011, elderly females (8.1%) outnumber elderly males (7.4%). Elderly females are a priority group for intervention, since studies have reported higher morbidity among elderly females than compared to males.^15,16

Of the men, 83.7% were currently married while only 35.5% of the women were currently married this is which according to Indian census is 76.8% and 40.1% respectively. 56.5% of the elderly females were widowed which is almost similar to the Indian estimates (58.3%). This could be due to the fact that in the Indian culture men marry women who are much younger, men remarry and the life expectancy of females is higher than that of males. 8(3.6%) of the elderly were separated of which six were females. The probable reasons for women as told by some women being separated from their husbands may be because they were chronically ill or the women were unable to bear children.

Most of the elderly 143(64.4%) belonged to the high socio economic status based on Standard of Living Index, while 10.8% and 24.8% of the elderly persons, belonged to low and middle socio economic status based on Standard of Living Index. This reflects the changing trend in rural India where in the younger generation is acquiring a better earning capacity thus raising the families socioeconomic status.

In our study, 22.1% of the elderly were completely independent financially. 18.5% of the elderly were partially dependent where as 59.5% of the elderly were completely dependent on the spouse or children. 72.6% of the elderly females were fully dependent financially on others as against to 42.9% of the men. According to NSSO 52nd round 30.1% of the rural Indian elderly were completely independent financially. Sample surveys conducted in India, and our study appears to reflect a high degree of financial insecurity among elders. The financial inadequacy was found to be of a higher degree among the female elderly compared to that of males.¹⁷

Hindi Mental Status Examination (HMSE) was used to assess the cognitive impairment of the elderly. 4.5% of the elderly had cognitive impairment. Cognitive impairment was higher in the old olds compared to that of oldest olds. In a study done in Delhi on older persons, 33 elderly (13.2%) were screened positive with HMSE.¹⁸ Higher levels of cognitive impairment (15.7%) were seen among the elderly in a study done in the west.¹⁹

The study was conducted in two villages of Bangalore district. 12.2% of the population was elderly persons in these two villages. Of the elderly 51% were females and 49% were males.95.5% of the elderly did not have any cognitive impairment and 4.5% of the elderly had cognitive impairment on assessment using Hindi Mental Status Examination. There is a further need to study cognitive impairment among community elderly to understand the impact of the same on their living.

Conflict of Interests

There were no funding sources. The authors declare that they have no Conflict of interests.