The older adult with impaired cognitive function continues to increase worldwide and is estimated to reach 131.5 million by 2050 [1]. Approximately 60% of the global cognitive impairment (dementia) burden is borne by developing countries; China and India contribute more than 25% of the global burden [2]. In India, the prevalence of a range of estimated mild cognitive impairment was between 15% and 33 % [3]. Nepal is not exception from this issue among older adults. Cognitive impairment (CI) is when a person has trouble remembering, concentrating or making decisions affecting their everyday life [4]. Its prevalence ranges from low to about one fourth in adults more than 65 years. It has been found that cognitively impaired older adults are at high risk of developing dementia in next few years [5]. Hence cognitive impairment is not only the common problem it could be the precursor for dementia. Cognitive impairment among older persons has different possible causes. In many cases, the cognitive problem worsens over time. Several benefits would be expe5cted if we could assess cognitive impairment and identify its causes at an early stage. The failure to evaluate memory or cognitive complaints is likely to hinder treatment of underlying disease and co morbid conditions, and may present safety issues for the patient and others [6]. Cognitive impairment has been found to have a substantial impact on patient’s lives and the close to them [7]. Early recognition allows for diagnosis and appropriate treatment, education and psychosocial support [8]. It is associated with increased use of health services and increased mortality [9]. Hence, research is required to determine the documentation of cognitive impairment to improve the condition of the patients. Very few studies have been performed on the cognitive function assessment among older persons in Nepal. Based on above situation our research designed with aim to know the prevalence of cognitive impairment among older persons visiting psychiatry department of a tertiary level hospitals in Kathmandu, which might support to view level of same problems in its community and also to plan supportive services in geriatric clinics.

Methods

It is a descriptive cross-sectional study which took place for six months duration (June to December 2021). Samples were taken from older persons visiting the psychiatry outpatient department of a tertiary level hospital (Shree Birendra Hospital, Kathmandu) within the study period. Written consent was obtained from each of the participants and then face to face interview done by researcher at outpatient Psychiatric department.

The sample size was calculated as follows:

N= Z² x p x q / e²

 = (1.96)² x 0.155 x (1-0.155) / 0.08²

 = 78.61

Where,

n= minimum required sample size

Z= 1.96 at 95% Confidence Interval (CI)

p= prevalence, 15.5% obtained from a similar study done by Pais et al [10]

e= margin of error, 8%

Sample size obtained was 90 using the cochrane’s formula with 95% CI, standard error of 8% and taking prevalence of cognitive impairment in the elderly is 15.5%. Screening of cognitive impairment was conducted using the Mini Mental State Examination (MMSE) tool of Folstein [11]. It is one of the oldest and most recognized tool against which other cognitive measures are compared [12]. It includes five cognitive domains: orientation, registration, attention and calculation, recall and language. The MMSE tool includes 30 questions related to long- and short-term memory and score ranges from 0 to 30, with lower scores indicating increasing severity of cognitive impairments, which classified as follows: scores between 24 and 30 indicate no CI, 18–23 as mild CI, and 0–17 as severe CI. [11]. The data were recorded in Microsoft Excel 2010 and analyzed using Statistical Package for the Social Sciences (SPSS) version 26.

Ethics Statement (If Any)

This study received approval from institutional ethical review committee (IRC) of the Nepalese Army Institute of Health science, Kathmandu.

Distribution of Socio-Demographic Variables

Among 90 patients, 50 (55.6%) were female and 40 (44.4%) were male. Regarding the previous occupation, most people were involved in agriculture followed by business and services. Majority of the participants 68.8 % could read and write which were considered being literate. Economic status was quite good (enough for 12 months) in 84.4% of the cases. Majority of the participants 85.6% were Hindu. Similarly, majority of them 80% lived in a joint family.

Distribution of Participants by Risk Factors

Among the total participants, 70 percent had current illness like hypertension and diabetes mellitus, 78.9 percent were non-smokers and 88.9 percent were non-alcoholic. In regards to the dietary habits, 82.2 percent were non-vegetarian while 17.8 percent were vegetarian. Frequency of visiting friends per month was greater than per week. Similarly, frequency of social activities was greater per month than per week.

Distribution of Participants with Different Grading Of Cognitive Impairment

The overall prevalence of cognitive impairment was 68.9 percent based on MMSE scores. Comparing the MMSE grading, mild cognitive impairment was seen in 50.0 percent of the population. Severe cognitive impairment was seen in 18.9 percent while 31.1 percent were normal.

Table 1: Distribution of Socio-demographic variables.

Table 2: Distribution of Participants by risk factors.

Table 3: Distribution of Participants with different grading of cognitive impairment.

Many epidemiological studies have documented the increased rate of progression of cognitive impairment to dementia and Alzheimer’s disease in patients [13]. It therefore, seems important to assess the cognitive impairment in patients to timely intervene the possible complications and create a healthier society. According to Alzheimer’s Disease International, approximately three quarters of people with dementia have not received a diagnosis, and therefore “do not have access to treatment, care and organized support that getting a formal diagnosis can provide”[14]. Early recognition allows for diagnosis and appropriate treatment, education, psychosocial support and engagement in shared decision-making regarding life planning, health care, involvement in research, and financial matters [8]. In our study, the baseline prevalence of cognitive impairment was 68.9 % among which 50.0 % had mild cognitive impairment and 18.9 % had severe cognitive impairment. Study done in tertiary care hospital in south India also showed the prevalence of cognitive impairment 31.0% among elderly with depression [15]. Similar study done in mental hospital in Addis Ababa showed 54.4% of cognitive impairment among major depressive disorder patients (MDD) [16]. In addition study done in community dwellings stated that in 93.0% Mild-Cognitive-Impairment and 39.1% had issues with memory among elderly people [17]. However, according to the study by Callahan CM the prevalence of cognitive impairment among all patients aged 60 years and older showed baseline as 15.7%; 10.5% had mild impairment and 5.2% had moderate to severe impairment [9]. The study done at the rural non-communicable disease clinic showed 26.6% prevalence of cognitive impairment among patients attending [18]. A community based cross sectional study using Mini-Mental State Examination scale score conducted in rural area of north India showed the prevalence of cognitive impairment was 36% [19]. The cross-sectional study conducted at rural health centers in Myanmar showed the rate of impaired cognitive function among participants was 29.9 % [20]. The cross-sectional study conducted in elderly Chinese people using Mini-Mental State Examination scale found the prevalence of cognitive impairment was 12.6% [21]. In our study, there were more females than males with cognitive impairment. Same result shown in the study done in tertiary hospital, South India [15]. Most of the participants were involved in agriculture. Most population followed Hinduism as a religion. Patients with undocumented cognitive impairment are less likely to be evaluated for reversible causes. Hence, it is important to perform research that shades on light the prevalence of cognitive impairment in our community.

Our study involved data from one institution using a smaller sample size. Hence, it may not be suitable to generalize the finding to the people of whole country. However, it provides the baseline information about the prevalence of cognitive impairment and encourages in performing research describing the causality and interventions for this particular disease.

This study showed high prevalence of cognitive impairment based on MMSE scores among elderly, which may or may not represent the diagnosis. High prevalence may be due to the sample of elderly are those attending psychiatric department of the hospital. However, other same studies done in different community also showed comparatively high prevalence of cognitive impairment. As cognitive impairment associated with frequent increased visit of health services with more risk of progression to dementia and increased mortality, hence better evidence based documentation of cognitive impairment is essential which would improve not only for diagnostic evaluations but also support patient management, counseling, with better outcomes.

The authors would like to thank to all the subjects for their participation and thanks to medical doctors of psychiatric department of Shree Birendra hospital, Kathmandu.

Author Contributions

All authors gave time in proposal writing and report preparation. Third author gave time for data collection and First and second authors gave time for data analysis.

Funding

Self-funding

Competing Interests

All the authors of this manuscript have declared that no competing in terests exist.

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