Abstract
BACKGROUND: Dementia imposes a significant burden to global health with currently
47 million people in the world suffering from it. It is estimated that by 2050 the number of
people affected will increase to 135 million, of which 71% will be living in lower and middle
income countries. Temporal trends in dementia incidence are a useful tool to understand the
disease epidemiology. Yet, for most countries dementia data is limited or incomplete. In
Sweden dementia incidence trends can be calculated using hospitalisations with reported
dementia from the Swedish National Inpatient Registry.
AIM: To describe and compare dementia incidence temporal trends within Sweden from
1980 to 2011, and to explore the relationship between incidence of dementia and
sociodemographic and diagnostic factors.
METHODS: 2,549,857 men and women with information regarding hospitalisation with
reported dementia from the Swedish birth cohorts 1920-1940 were followed for 31 years.
Outcome was ascertained through linkage to the Swedish National Inpatient Registry via
lopnr (a unique personal serial number). Dementia hospitalisation, sex and educational level
were classified into categorical variables. Dementia incidence rates were obtained through
Poisson regression model. Cox regression analyses were performed to determine risk hazard
ratios (HR) with 95% confidence intervals (CI). Descriptive statistics were used to explain
the temporal trends.
RESULTS: In Sweden overall dementia hospitalisations and crude incidence trends (not
adjusted for age) increased during 1980-2011. Women and individuals with low educational
level showed the highest incidence rates. Yet, during 1997-2011 the risk of being hospitalised
with dementia was lower for women (HR: 0.94; 95% CI: 0.93 to 0.96) and was lower among
individuals with high educational level (HR: 0.91; 95% CI: 0.90 to 0.93), age-adjusted.
Throughout the studied period age was a driver for dementia incidence trends: the oldest age
categories consistently presented the highest dementia incidence rates.
CONCLUSION: Swedish dementia incidence trends continued to rise from 1980 to 2011
but differed depending on sex and education. These findings will inform public health policy
regarding temporal trends and may help direct the global action against dementia.
Abstract
No Swedish abstract available.
