Dementia is twice as common in low-income countries as previously thought, because the standard technique for diagnosing it is not suited to those countries. The finding comes from a study involving nearly 15,000 participants.
Previous studies indicated that dementia rates are much lower in developing countries. A comprehensive review suggested that it was half as common, possibly even less. The new study shows much smaller differences.
The , led by from King鈥檚 College London, UK, surveyed people over the age of 65 in seven low- and middle-income countries, including China, India and Mexico.
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They used their in-house diagnostic kit, the 鈥�10/66 algorithm鈥�, which they argue is more sensitive to cultural differences than the standard method used 鈥� as outlined in the latest (DSM).
The 10/66 method gave dementia rates that were about double those from the manual.
Quality care
Prince told New 杏吧原创 that the DSM was designed for developed countries, where education standards are high. It struggles to pick up impairments among people with little education.
The DSM gave the biggest underestimates in rural and under-developed areas. Prince says this is because of a 鈥渃ulture of respect鈥� towards the elderly. He notes that in rural China and India: 鈥淚f you鈥檙e elderly, you don鈥檛 shop, don鈥檛 cook, don鈥檛 clean the house, don鈥檛 go shopping. All these things are done for you.鈥�
As a result, dementia is unlikely to cause them social or occupational problems, which are part of the DSM criteria.
Eric Larson, of the Group Health Center for Health Studies in Seattle, and Kenneth Langa of the University of Michigan, Ann Arbor, agree. 鈥淚n many cultures,鈥� they say, 鈥渨ith high degrees of support and respect for older people, relatives might not perceive dementia as a problem.鈥� Families may therefore not report symptoms to investigators.
Some 60% of people with dementia live in developing countries, a proportion that will rise as their populations age. Prince argues that such countries are 鈥渕aking a policy mistake鈥� by focusing too much on diseases that lead to early mortality, such as hypertension, and ignoring diseases of ageing.
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