Indirect Estimation of Dementia Prevalence and Its Geographical Variation Using the Claim Data in Iran

Dementia is a chronic disease that imposes a huge financial and social burden on the health system. Knowledge of the prevalence of dementia is essential for healthcare planning and ensuring that there is an adequate service for people with the condition. Considering that the prevalence and geographical variation of dementia are not well known in Iran, the present study was conducted to investigate the prevalence of dementia and its geographic variations in Iran.

In this study, the prevalence of dementia was estimated indirectly using the frequency of prescribed specialized medicines in one year by generic and brand names in each province. Choropleth maps were used to visually assess the geographical variation of dementia prevalence at the provincial level. Moran I and Getis-Ord Gi (Gi) geographical tests were used to investigate the spatial autocorrelation and geographical variability of dementia prevalence at a significant level of 0.05, respectively.

In this study, the prevalence of dementia was 49.6 and 508.9 in 100000 in the general and over 60-year population, respectively. In the general population, the lowest prevalence was in Hormozgan Province (9.4/100000) and the highest prevalence was in East Azarbayjan Province (96.4/100000). In the over 60-year population, the lowest prevalence was in Hormozgan Province (141.5/100000) and the highest in Isfahan Province (862.5/1000000). According to Moran I and Getis-Ord Gi (Gi) tests, spatial autocorrelation and geographical variability of dementia prevalence were not significant.

The prevalence of dementia in the Iranian over 60-year population is lower compared to western countries; however, it is comparable with the reported dementia prevalence from developing countries. It should be noted that the dementia prevalence is high, similar to developed countries, in some developed provinces of Iran.