Cognition declines with aging. Mild cognitive impairment turns into dementia with an estimated rate of 10% each year. Elderly population, and of particular female gender, are at higher risk for dementia^5,6. Reported new cases of dementia are alarmingly high in the developing countries⁷. The financial burden faced by these developing countries may be more than can be handled by them as the cost of home and institutional care for demented patients is very high⁸.

Depression is used in a broad sense to describe a syndrome that includes a constellation of physiological, affective and cognitive manifestations. Depression may range in severity from mild symptoms to more severe forms that include delusional thinking, excessive somatic concern and suicidal ideation over long periods of time⁹. Prevalence of depression in the Asia- Pacific region is comparable to that of the Western world¹⁰. Depression is the most common psychiatric disorder in the elderly; it is commonly misdiagnosed and under treated. The untreated depressed elderly have significant clinical and social implications as these disorders decrease an individual’s quality of life and increase dependence on others. Depression causes functional impairment and imposes an immense burden on individuals, communities and heath services.

There have been reports suggesting that elderly people with depression appear to be at a greater risk of developing dementia and cognitive decline^11,12. This strong association between depression and cognitive impairment may even be bidirectional¹³.

Geriatrics and psycho geriatrics are emerging specialties in Malaysia, so to date there has been relatively little research in these areas. There is a dearth in research on dementia and depression among the residents of elderly care institutions in Malaysia.

The objective of the study was to determine the prevalence of dementia and depression and their associated risk factors among residents of a privately run old folks home in Penang Malaysia.

The prevalence of cognitive impairment was 12.3% (19). As shown in table III, there is a statistical significance between age and cognitive impairment (p=0.032). Illiterates were six folds more likely to be cognitively impaired compared with literates (OR 5.57, 95% CI 2.02-15.34). Participants with history of unemployment were 9 times (OR 9.33, 95% CI 2.88-30.20) more likely to be cognitively impaired. Those who were functionally dependent were 5 times (OR 4.52, 95% CI 1.54-13.29) more likely to be cognitively impaired compared to those who were independent. Factors like gender, race, religion, marital status, next of kin, presence of chronic illness and nutrition were not found to be significantly associated with risk of dementia.

Figure 3

Table III: Risk factors associated with cognitive impairment

A binary logistics regression was done using ADL, history of employment, age and education as predictor variables as shown in table IV. History of employment (OR 9.88. 95% CI 2.49;31.21) and education (OR 5.22. 95% CI 1.66-16.38) were found to be significant predictor variables. The model had -2 likehood ratio of 83.508, Cox and Snell R squared 0.186 and Nagelkerke R square 0.354.

Figure 4

Table IV: Logistic regression for cognitive impairment

Out of the 155 residents who had participated in the survey, 19 were ineligible for assessment using the GDS as they scored less than 5 in the ECAQ assessment. The remainder 136 were screened for depression using GDS. The prevalence of depression in this study was 20.6% (28). Five (3.7%) had severe depression and 23 (16.9%) had mild depression.

As shown in table V, residents who were functionally dependent (OR 2.67, 95% CI 1.14-6.25) were almost three times more likely to be depressed compared to residents who were functionally independent. Factors like gender, age, race, marital status, education level, previous occupation, next of kin, presence of chronic illnesses and BMI were not found to be significantly associated with depression.

Figure 5

Table V: Risk factors associated with depression

A binary logistics regression was done using disability, gender and BMI as predictor variables as shown in table VI. Being functionally dependent (OR 2.87. 95% CI 1.181-6.983) was found to be a significant predictor variable. The model had -2 likehood ratio of 129.364, Cox and Snell R squared 0.062 and Nagelkerke R square 0.097.

Figure 6

Table VI: Logistic regression for depression

Dementia characterized by a decline in memory, language and other cognitive functions, is known to be a common problem among the elderly. It is expected that the number of people inflicted with dementia will double in the next 20 years⁷. In the present study, the prevalence of cognitive impairment among residents in the old folk’s home was considerably lower than in studies done elsewhere, where the prevalence of dementia in residential and nursing homes was reported as high as 80%¹⁹. The prevalence of cognitive impairment in this study is also lower than that of a similar study carried out in a state run residential home in north Malaysia which recorded a prevalence of 36.5%²⁰. Similar high prevalence rates were also noted in studies conducted in nursing homes in Singapore (48%) ²¹ and the United Kingdom (66.9%)²². Generally, cognitive impairment rates are much higher in institutions for the elderly than in the community. But the prevalence rate of this study is even lower than the prevalence rates of cognitive impairment in other community based studies in Malaysia^23,24. Possibly because being a privately run institution, it is incapable of managing demented residents and hence it refers them to either government run institutions or the next of kin are told to take them back for nursing care.

Although dementia is not a natural part of ageing, its prevalence increases with age. The finding of this study concurs with the findings of other studies conducted locally ^24,25 and abroad ^26,27 which shows that the prevalence of moderate to severe cognitive impairment increases steeply with age.

Association between the dependence on the activities of daily living and cognitive impairment was significantly proven in this study as well as another study carried out among residents of an old folk’s home in north Malaysia²⁰. This is because the loss of a patient's ability to independently perform daily activities is an important aspect of the disease. In fact, a study has shown that relatively small degree of loss of cognitive skills in patients with mild-to-moderate dementia can lead to an increased risk of losing the ability to live independently ²⁸.

Residents who were previously unemployed and those who were illiterate had higher risk of being cognitively impaired. Research has also shown that each additional year of education is associated with an 11 percent reduced risk of developing dementia, as those with higher education were better able to compensate for the effects of the brain disorder²⁹. Studies have suggested that physical activity³⁰, mentally demanding work and higher managerial positions ³¹ have a positive cognitive status in later life. This fact may explain for the low prevalence of cognitive impairment in this study where 71.6% of the residents were literate and over 90% of them were previously employed. But not all types of occupations have a protective effect towards cognitive impairment. Studies conducted in France ³² and Taiwan ³³ found that people in lower class of occupations have a higher risk of cognitive impairment. Possible explanations for the association of occupation and cognitive impairment could be due to the higher exposure to toxic exposures, the levels of psychosocial stress in different occupations and the level of mental stimulation required in the job.

As with the prevalence of cognitive impairment, the prevalence of depression in the elderly is also much higher in residential homes for the elderly ³⁴. The prevalence of depression in this study was found to be much higher than that of studies conducted in the community in Malaysia. The prevalence of depression has been shown to range around 8% in central Malaysia ³⁵ but much higher in the north where the prevalence of depression among the elderly in the community has been reported to be as high as 48.4%²⁴ and 67% in a state run residential home in north Malaysia ²⁰.

One of the most important factors determining the life satisfaction of the elderly is their level of functional independence. Independence in activities of daily living is important for the quality of life in the elderly. Maintaining an independent lifestyle in the elderly and the resulting quality of life is dependent on the ability of the person to carry out activities of daily living, including social activity. Physically impaired older people tend to become socially isolated, which may result in the exacerbation of mental health problems, particularly depression³⁶. Older adult with loss of functional autonomy are more susceptible to have symptoms of psychological distress. Studies show that 27 to 48% of older adults living in the community suffer from psychological distress symptoms. People who regain some of their functional anatomy experience a reduction in psychological distress symptoms ³⁷. In this study being functionally dependent was a risk factor for depression. This is in concordance with studies conducted in Indonesia, Vietnam and Japan that found subjects with depression had significantly lower scores for ADL and Quality of Life than those without depression³⁸. Similarly another study conducted in north Malaysia among elderly in an old folks home also found higher rate of depression among those who were disabled²⁵.

One of the limitations of our study is a relatively small sample size in comparison to other studies carried out elsewhere. This is because this study is conducted in a privately run institution which has a rather limited capacity to accommodate too many residents. In addition, being privately run, it is incapable of managing demented residents and hence it refers them to either government run institutions or the next of kin are told to take them back for nursing care. Thus, this explains the lower prevalence rate of cognitive impairment.