Prevalence of Dementia and Associated Factors among Older Adults in Iran: National Elderly Health Survey (NEHS)

Background: the prevalence of cognitive impairment and dementia is increasing in Iran and the world. There is no study available on the prevalence of dementia at the national level in Iran. This study aimed to report the rate of dementia at the national level in Iran. Methods: The National Elderly Health Survey (NEHS) was a cross-sectional study with multistage cluster random sampling on people aged 60 years in Iran. Dementia was diagnosed by trained general practitioners using Brief Cognitive Assessment Tool (BCAT). In this study, the dementia diagnosis rate was considered as the ratio of individuals previously diagnosed with dementia to individuals considered as dementia. Analyses were carried out using survey analysis method. The provincial rates were standardized based on the Iranian population in 2011 and the national rate was standardized based on WHO standard populations. Association between risk factors and dementia was assessed using a multivariable logistic regression model Results: The overall crude prevalence of dementia among people aged >= 60 years was 7.9% (8.7% in women and 6.9% in men) and age standardized dementia prevalence rate in Iran based on WHO standard population was 8.1% (9.6% in women and 6.5% in men). The prevalence of dementia was observed as 3.7% among people aged 60-64 years, 6.2% in the age-group 65-69 years, 10.4% in the age-group 70-74 years, 14.4% in the-age-group 75-79 years, and 13.0% in the age-group >= 80 years. West Azerbaijan had the lowest and North Khorasan had the highest age-sex adjusted prevalence rate of dementia. Our results indicated that only 21.2% of subjects with dementia were diagnosed. We observed that diabetes mellitus, depressed mood, illiteracy, and increased age were associated with dementia. Conclusion: It seems that dementia is more common in Iran than many other countries. However, the rate of dementia diagnosis is much lower than that in developed countries.