Fracture risk among First Nations people: a retrospective matched cohort study

Background

Canadian First Nations people have unique cultural, socioeconomic and health-related factors that may affect fracture rates. We sought to determine the overall and site-specific fracture rates of First Nations people compared with non-First Nations people.

Methods

We studied fracture rates among First Nations people aged 20 years and older (n = 32 692) using the Manitoba administrative health database (1987–1999). We used federal and provincial sources to identify ethnicity, and we randomly matched each First Nations person with 3 people of the same sex and year of birth who did not meet this definition of First Nations ethnicity (n = 98 076). We used a provincial database of hospital separations and physician billing claims to calculate standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for each fracture type based on a 5-year age strata.

Results

First Nations people had significantly higher rates of any fracture (age- and sex-adjusted SIR 2.23, 95% CI 2.18–2.29). Hip fractures (SIR 1.88, 95% CI 1.61–2.14), wrist fractures (SIR 3.01, 95% CI 2.63–3.42) and spine fractures (SIR 1.93, 95% CI 1.79–2.20) occurred predominantly in older people and women. In contrast, craniofacial fractures (SIR 5.07, 95% CI 4.74–5.42) were predominant in men and younger adults.

Interpretation

First Nations people are a previously unidentified group at high risk for fracture.Most of the epidemiologic data describing fractures have been derived from white populations,¹ although it is known that there is ethnic variation in the epidemiology of fractures.^2,3,4 Canadian First Nations people are known to suffer from a heavy burden of medical and social problems that may affect fracture rates.⁵ To date, however, there have been no satisfactory studies of fracture rates among North American Aboriginal groups. We sought to determine the overall and site-specific fracture rates of First Nations people compared with non-First Nations people in Manitoba.