La démence est l’une des principales causes d’invalidité et de dépendance chez les personnes âgées et il n’existe pas d’interventions efficaces. Par conséquent, il semble particulièrement encourageant que des études récentes suggèrent une première baisse potentielle de l’incidence de la démence, c’est-à-dire un nombre réduit de nouveaux cas de démence, dans des pays à revenu élevé.
Plain language summary
Population aging around the world is driving an increase in numbers of people living with dementia. Already, dementia is among the leading causes of disability and dependency in old age, and effective interventions are currently not available. Therefore, it seems particularly encouraging that recent studies suggested a potential first-time decline in dementia incidence, that is, a smaller number of new cases of dementia in later periods of time, in high-income countries (HIC). The wealth advantage of HIC may have facilitated beneficial environments, for example, good access to education, nutrition, and health care, allowing for better population health, and hence, leading to fewer cases of dementia. Our aim was to systematically search for recent studies on trends in dementia incidence from HIC and to statistically synthesize data from identified studies of good methodological quality. We were able to identify seven studies, and five were included in the meta-analysis. Our results suggest favorable trends in dementia incidence in Western HIC (stabilizing/decreasing); however, the decline does not reach statistical significance. Moreover, there may be reverse trends in other HIC, as exemplified by an observed increase in dementia incidence in Japan. Overall, there may be differential trends in dementia incidence in HIC, reflecting varying life conditions and life experiences beyond beneficial environments in such wealthy societies. Ultimately, further well-conducted studies on trends in dementia incidence are needed to add to this growing research field in order to come to more robust conclusions. Our work may inform future studies.
ROEHR, Susanne, PABST, Alexander, LUCK, Tobias et RIEDEL-HELLER, Steffi G, 2018. Is dementia incidence declining in high-income countries? A systematic review and meta-analysis. Clinical Epidemiology [en ligne]. 18 septembre 2018. Vol. 10, pp. 1233‑1247. DOI 10.2147/CLEP.S163649.