Trends in stroke incidence in Auckland, New Zealand, during 1981 to 2003.
OBJECTIVE
Long-term trends in stroke incidence in different populations have not been well characterized, largely as a result of the complexities associated with population-based stroke surveillance.


METHODS
We assessed temporal trends in stroke incidence using standard diagnostic criteria and community-wide surveillance procedures in the population (approximately 1 million) of Auckland, New Zealand, over 12-month calendar periods in 1981-1982, 1991-1992, and 2002-2003. Age-adjusted first-ever (incident) and total (attack) rates, and temporal trends, were reported with 95% confidence intervals (CIs). Rates were analyzed by sex and major age groups.


RESULTS
From 1981 to 1982, stroke rates were stable in 1991-1992 and then declined in 2002-2003, to produce overall modest declines in standardized incidence (11%; 95% CI, 1 to 19%) and attack rates (9%; 95% CI, 0 to 16%) between the first and last study periods. Some favorable downward trends in vascular risk factors such as cigarette smoking were counterbalanced by increasing age and body mass index, and frequency of diabetes, in patients with stroke.


CONCLUSIONS
There has been a modest decline in stroke incidence in Auckland over the last 2 decades, mainly during 1991 to 2003, in association with divergent trends in major risk factors.
Anderson
Craig S
CS
School of Population Health, Faculty of Medicine and Health Sciences, University of Auckland, New Zealand. canderson@thegeorgeinstitute.org
Carter
Kristie N
KN
Hackett
Maree L
ML
Feigin
Valery
V
Barber
P Alan
PA
Broad
Joanna B
JB
Bonita
Ruth
R
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009520:New Zealand; D011159:Population Surveillance; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking; D020521:Stroke / Q000175:diagnosis* / Q000453:epidemiology* / Q000209:etiology; D013997:Time Factors