Age at stroke: temporal trends in stroke incidence in a large, biracial population.
OBJECTIVE
We describe temporal trends in stroke incidence stratified by age from our population-based stroke epidemiology study. We hypothesized that stroke incidence in younger adults (age 20-54) increased over time, most notably between 1999 and 2005.


METHODS
The Greater Cincinnati/Northern Kentucky region includes an estimated population of 1.3 million. Strokes were ascertained in the population between July 1, 1993, and June 30, 1994, and in calendar years 1999 and 2005. Age-, race-, and gender-specific incidence rates with 95 confidence intervals were calculated assuming a Poisson distribution. We tested for differences in age trends over time using a mixed-model approach, with appropriate link functions.


RESULTS
The mean age at stroke significantly decreased from 71.2 years in 1993/1994 to 69.2 years in 2005 (p < 0.0001). The proportion of all strokes under age 55 increased from 12.9% in 1993/1994 to 18.6% in 2005. Regression modeling showed a significant change over time (p = 0.002), characterized as a shift to younger strokes in 2005 compared with earlier study periods. Stroke incidence rates in those 20-54 years of age were significantly increased in both black and white patients in 2005 compared to earlier periods.


CONCLUSIONS
We found trends toward increasing stroke incidence at younger ages. This is of great public health significance because strokes in younger patients carry the potential for greater lifetime burden of disability and because some potential contributors identified for this trend are modifiable.
University of Cincinnati College of Medicine, Cincinnati, OH, USA. brett.kissela@uc.edu
Brett M
BM
Kissela
Jane C
JC
Khoury
Kathleen
K
Alwell
Charles J
CJ
Moomaw
Daniel
D
Woo
Opeolu
O
Adeoye
Matthew L
ML
Flaherty
Pooja
P
Khatri
Simona
S
Ferioli
Felipe
F
De Los Rios La Rosa
Joseph P
JP
Broderick
Dawn O
DO
Kleindorfer
D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D044383:Black People; D002545:Brain Ischemia / Q000453:epidemiology*; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D007629:Kentucky / Q000453:epidemiology; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology*; D013997:Time Factors; D044465:White People; D055815:Young Adult; D001741:Black or African American