DISCUSSION
We found a high prevalence of MCI and dementia among Albanian older patients in our study, detected by using different tests. However, using the MoCA test and adjusting for the level of education, the prevalence of dementia was 4,37 % which is consistent with the global prevalence found for those aged 60 years or older by Prince et alin 2013, ranging from 5 to 7 % in most world regions.(14) The systematic review by Russ et al found extended evidence of variations in the prevalence of dementia by geographical regions. (15)
Our study was conducted among older patients in two cities, Shkoder, the larger city in north Albania and Tirana, capital and central city of Albania. According to both tests employed, prevalence of MCI was higher in Shkoder compared to Tirana. Few studies have estimated the prevalence of dementia in Albania. In a study conducted in 1999 in Tirana, the total prevalence of dementia for people aged more than 60 years old resulted 7.75%, which is similar to our findings. In this case, the MMSE was used as screening test, followed by clinic and radiological evaluations according to ICD 10 diagnostic criteria for dementia.(16)
Another study performed in 2012 in two geographic areas with different socioeconomic level – Tirana (central Albania) and Saranda (south Albania) – found besides other neurological disorders, a prevalence for dementia of 9.6 % (7.7-11.5), similar between the two areas.17 None of the two previous studies evaluated mild cognitive impairment, neither did they include patients from northern regions of Albania.
Studies on MCI reported in various European studies since 1995 presented substantial heterogeneity, as reported by Alexander et al , which pointed out that the majority of studies reported an increase of dementia prevalence with patients 75 years or older. Furthermore, pooled prevalence of dementia increased constantly from 55 years old, ending up at 44.7 % in patients older than 95 years.(18) The factors clearly associated with higher prevalence of dementia and MCI in our study were gender, age and level of education, as observed in many studies. (19,20,21)We also found a higher prevalence of MCI among patients in the city of Shkoder compared to Tirana, which may be partly explained by the higher socioeconomic and educational level of the latter.
According to a recent report by the Alzheimer Society of Canada, there is great variability regarding the prevalence of dementia depending on the different methodology and definitions used, as well as data source. Another weak point of the majority of studies for dementia prevalence estimation is not including MCI in the projections.(22) In our study, there is very poor agreement between the two types of tools employed for the detection of MCI, namely MoCA / MoCA B and mini-cog. The Kappa Index of 2,38 % highlights the differences between the tools used. The majority of published studies have compared the screening tool MoCA with MMSE, showing its superiority in the detection of individuals with MCI. (23)Nevertheless, there is a lack of studies comparing MoCA to mini-cog, as well as a restricted number of studies that evaluate diagnostic accuracy of mini-cog for dementia in primary healthcare. (24)
Dementia is often going under-detected until the late stage, having a deep impact in patients’ and caregivers´ quality of life, delaying potentially beneficial nonpharmacological and pharmacological treatments. A systematic review by Lang et al including 23 studies calculated a pooled rate of undiscovered dementia of 61.7 %, with higher rates in China, India compared to Europe and North America, more common in community settings than assisted living facilities, and men younger than 70 years old. Focused attempts to tackle the growing problem of undiagnosed dementia, especially among low socioeconomic background countries, are necessary to mitigate inequality; early detection of MCI might be the key to early detection and management of this syndrome. (25,26)