Brandy R. Matthews, MD

As the life expectancy in population-dense, low-income nations such as China and India continues to improve the incidence and prevalence of dementia and other illnesses associated with aging are also likely to increase, creating new socioeconomic hardships. Previous estimates of the incidence of dementia in China were based on an incomplete review using only 25 studies in the Chinese literature published from 1980 to 2004, with supplemental information from publically available databases. The present systematic review included 89 studies published between 1990 and 2010 in Chinese or English, identified via PubMed, China National Knowledge Infrastructure, and Wanfang (a medical database). Most of the studies had >1000 participants, and 95% of the dementia cases were defined by well-established criteria. Of the 75 cross-sectional studies included, 68% involved a multidisciplinary assessment by neurologists and psychiatrists.

Using demographic data from the United Nations to compare to the data from more than 340,000 participants in these studies, the authors estimated that 9.19 million people in China had dementia in 2010, and 5.69 million had Alzheimer disease. The estimated prevalence correlated positively with advancing age, as would be predicted from other populations. However, the estimated prevalence of all dementias in participants aged 95 to 99 years was unexpectedly high, increasing from 42.1% in 1990 to 60.5% in 2010.

Citation(s):

Chan KY et al. Epidemiology of Alzheimer's disease and other forms of dementia in China, 1990–2010: A systematic review and analysis. Lancet 2013 Jun 8; 381:2016.