2008 (Oct) Canadian Diabetes Association Annual Conference, poster presentation by BRAID Research

1. Increasing Incidence and Prevalence of Diabetes Among The Status
Aboriginal Population in Rural and Urban Alberta, 1995-2006
1995-
Jeffrey A. Johnson, PhD1,2 Stephanie U. Vermeulen, MSc2 Greg Hugel, MSc2 Ellen Toth, MD3
Brenda R. Hemmelgarn, PhD, MD4 Kelli Ralph-Campbell, BA3 Malcolm King, PhD3
(1)School of Public Health, University of Alberta, Edmonton, AB. (2)Institute of Health Economics, Edmonton, AB,
(3)Department of Medicine, University of Alberta, Edmonton, AB, (4)Department of Medicine, University of Calgary, Calgary, AB.
Background
Results
• The prevalence of diabetes is three to five times
higher among Aboriginal Canadians compared to the Table 1. Diabetes Incidence by sex and location of residence amongst Figure 2. Age-adjusted prevalence rates of diabetes among Status
non-Aboriginal population. Status Aboriginal Canadians 1995 and 2006 Aboriginal Canadians by sex and location of residence, 1995-2006
• A variety of factors are believed to contribute to these
Overall Men Women
increased rates, including genetic susceptibility and
environmental factors. Urban Rural Urban Rural Urban Rural
• Aboriginal Canadian women have higher rates of 1995
diabetes compared to their male counterparts; where New diabetes cases (n) 76 182 32 82 44 100
the opposite relationship is true among non- Population at risk (n) 17183 25347 8,040 12,895 9,143 12,452
Aboriginal Canadians. Crude incidence (per 1000) 4.4 7.2 4.0 6.4 4.8 8.0
• Location of residence is an important determinant in Adjusted* incidence (per 1000) 8.1 11.2 7.4 9.7 8.8 12.8
the development and management of diabetes where (95% CI) (5.9‐10.8) (9.5‐13.2) (4.9‐10.6) (7.6‐12.2) (5.4‐13.5) (10.0‐16.0)
individuals living in rural areas have increased 2006
treatment gaps and acute complications with their New diabetes cases (n) 235 306 109 153 126 153
diabetes. Population at risk (n) 33525 31454 16,249 15,988 17,276 15,466
Crude incidence (per 1000) 7.0 9.7 6.7 9.6 7.3 9.9
Identification of Status Aboriginal
Adjusted* incidence (per 1000) 10.8 12.6 10.7 13.0 10.9 12.3
• The term “Status Aboriginal” refers to a person (95% CI) (9.0‐12.9) (11.1‐14.3) (8.3‐13.5) (10.9‐15.5) (8.3‐14.2) (10.1‐14.7)
residing in Alberta who is registered under the federal
Indian Act and is entitled to Treaty Status with the
% change in adjusted* incidence rate 33.8% 12.5% 44.7% 34.6% 24.8% ‐3.9%
Government of Canada.
*rates are age-sex adjusted for Overall, and age-adjusted for Men and Women, using the 2001 Alberta population from the Canadian Census as standard.
• Aboriginal people in Alberta who were not registered Summary of Results in Status Aboriginals
– such as Aboriginal people without Treaty status or Incidence
Figure 1. Age-adjusted incidence rates of diabetes among Status Aboriginal
Métis – were included in the non-Aboriginal group. • Age and sex-adjusted diabetes incidence rates increased by 34% in those with
Canadians by sex and location of residence, 1995-2006
urban residences and 13% for those in rural areas from 1995-2006.
Diabetes Case Definition • After adjusting for differences in age, incidence rates were 22% (95%CI: 11-
To identify individuals with DM using Alberta Health and Wellness 33%) higher for men and 27% (95%CI: 18-38%) higher for women in rural
administrative database, ADSS applied the NDSS* algorithm:
locations compared to urban locations (p<0.001).
A. One hospitalization with an ICD-9 code of 250 (diabetes Prevalence
mellitus), selected from all available diagnostic codes on the
Hospital Discharge Abstract for years 1995-2001, or equivalent • Age and sex-adjusted diabetes prevalence rates increased 22% among those
ICD-10 codes (E10-14, diabetes) for years after 2001/2002; OR, with urban residences compared to 35% increase for those in rural areas from
B. Two physician claims with an ICD-9 code of 250 (diabetes 1995-2006.
mellitus) within two years. • Diabetes prevalence rates among women were higher than men in all years
(p<0.001), regardless of location of residence, although the increases across
Location of Residence time were smaller.
• Location of residence was based on the postal code
for home address in the Stakeholder Registry, with Key Messages
the second digit ‘O’ in the Forward Sortation Area • Diabetes prevalence and incidence were highest in Status Aboriginal women,
(FSA) indicating a rural residence; all other digits but have increased faster in men over the past decade, regardless of location of
indicated urban residence. residence.
• These trends have important implications for targeted prevention and health
Statistical Analysis promotion strategies for Status Aboriginal Canadians.
• Age- and sex- adjusted to the Alberta population
from the 2001 Canadian Census.
• Weighted logistic regression was used to test for
trends of diabetes incidence and prevalence over Funding provided by:
time, using year as an ordinal variable. .