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12 | advancing Knowledge
Missing dementia
Is dementia less common in developing countries?
New research suggests not.
Care and the
community
The secret to informed consent may
lie in community engagement.
1 2
The reported prevalence of dementia
in developing countries is surprisingly
low. Now, an international collaboration
led by Martin Prince at the Institute of
Psychiatry has found that its
prevalence has been substantially
underestimated in low- and middleincome
countries, and that it is almost
as common as in developed countries.
Moreover, dementia is imposing a
considerable psychological and
economic burden on large numbers
of carers.
Professor Prince leads the 10/66
Dementia Research Group, an
international collaboration assessing the
impact of dementia and related conditions
in low- and middle-income countries. It
derives its name from the fact that less
than one-tenth of population-based
dementia research has focused on the
two-thirds or more of all people with
dementia who live in developing countries.
Members of the collaboration assessed
almost 15 000 people over the age of 65
in 11 countries, using culturally sensitive
tools to factor out different perceptions
of ageing and dementia.
The results suggested that there is a
‘hidden epidemic’ of dementia, its
prevalence in urban settings in Latin
America comparable to those seen in
Europe and the USA. By 2040, the
number of people with dementia in Latin
America – more than nine million – is
likely to match that in North America.
Moreover, as healthcare is generally
limited in such regions, patient care
usually falls to spouses or other family
members. Dementia is the single biggest
factor contributing to dependency,
creating significant economic and
psychological pressures: carers are
often forced to cut working hours and
are at high risk of depression or other
forms of mental distress.
Previous underestimates may reflect the
fact that people in lower-income countries
are less likely to seek help for elderly
relatives showing signs of dementia – it is
often seen as a ‘natural’ part of ageing.
The findings suggest that there is a major
health burden going unaddressed in
many countries. More positively,
intervention studies in Russia and India
carried out by the 10/66 Group (funded
by the World Health Organization)
suggest that simple home-based
interventions can provide significant
benefits to both carers and patients.
Llibre Rodriguez JJ et al. Prevalence of dementia in
Latin America, India, and China: a population-based
cross-sectional survey. Lancet 2008;372(9637):
464–74.
Llibre Rodríguez J et al. The prevalence, correlates and
impact of dementia in Cuba. A 10/66 Group
population-based survey. Neuroepidemiology
2008;31(4):243–51.
Informed consent – ensuring that
people who participate in research do
so voluntarily and with a full awareness
of what is involved – is a thorny ethical
issue in developing countries. Research
in Kenya and Malawi is revealing how
informed consent operates in the field,
and emphasising the importance of
pro-active community engagement.
Although often discussed, relatively little
empirical research into informed consent
has been carried out – a deficit being
tackled by Joseph Mfutso-Bengo in
Malawi and Sassy Molyneux and
colleagues in Kenya.
Dr Mfutso-Bengo and Dr Molyneux have
explored the reasons why people do or
do not volunteer to take part in trials. It is
often assumed that participants believe
they will benefit from the intervention
being tested – the so-called therapeutic
misconception. In fact, a broader
motivation is a desire to access the better
general healthcare often provided to
participants. By contrast, discussions
with community members suggested
several reasons why people decline to
take part in trials, including potential
volunteers’ lack of awareness of health
research and investigators adopting
culturally insensitive practices.
In Kenya, Dr Molyneux, Vicki Marsh,
Dorcas Kamuya and others have focused
on strengthening relations between the
Images
1 In Latin American countries such as Cuba, dementia may be more
common than thought.
2, 3 Engaging with the local community in Malawi.
4 A young child in a hospital in Malawi.