Geographic methods for understanding and responding to disparities in mammography use in Toronto, Canada.
OBJECTIVE
To use spatial and epidemiologic analyses to understand disparities in mammography use and to formulate interventions to increase its uptake in low-income, high-recent immigration areas in Toronto, Canada.


METHODS
We compared mammography rates in four income-immigration census tract groups. Data were obtained from the 1996 Canadian census and 2000 physician billing claims. Risk ratios, linear regression, multilayer maps, and spatial analysis were used to examine utilization by area for women age 45 to 64 years.


METHODS
Residential population of inner city Toronto, Canada, with a 1996 population of 780,000.


METHODS
Women age 45 to 64 residing in Toronto's inner city in the year 2000.


RESULTS
Among 113,762 women age 45 to 64, 27,435 (24%) had received a mammogram during 2000 and 91,542 (80%) had seen a physician. Only 21% of women had a mammogram in the least advantaged group (low income--high immigration), compared with 27% in the most advantaged group (high income--low immigration) (risk ratio, 0.79; 95% confidence interval, 0.75 to 0.84). Multilayer maps demonstrated a low income-high immigration band running through Toronto's inner city and low mammography rates within that band. There was substantial geographic clustering of study variables.


CONCLUSIONS
We found marked variation in mammography rates by area, with the lowest rates associated with low income and high immigration. Spatial patterns identified areas with low mammography and low physician visit rates appropriate for outreach and public education interventions. We also identified areas with low mammography and high physician visit rates appropriate for interventions targeted at physicians.
Glazier
Richard Henry
RH
Inner City Health Research Unit, Department of Family and Community Medicine, St. Michael's Hospital, 30 Bond Street, Toronto, Ontario, Canada M5B 1W8. richard.glazier@utoronto.ca
Creatore
Maria Isabella
MI
Gozdyra
Piotr
P
Matheson
Flora I
FI
Steele
Leah S
LS
Boyle
Eleanor
E
Moineddin
Rahim
R
D016000:Cluster Analysis; D004641:Emigration and Immigration; D005260:Female; D006801:Humans; D007182:Income; D008327:Mammography / Q000706:statistics & numerical data*; D008875:Middle Aged; D009864:Ontario; D012959:Socioeconomic Factors; D014505:Urban Population / Q000706:statistics & numerical data*