Trends in Hip Fracture Rates in Canada

Over the next few decades, hip fractures will be a major public health concern as the number of elderly, a population at high risk for osteoporosis, increases substantially. The rising incidence of hip fracture is a concern for both afflicted individuals and the health care system because these fractures are associated with significant morbidity, mortality, and costs. This study investigated trends of hip fractures in Canada from 1985 to 2005 through analysis of national databases on hospitalization and morbidity. The primary study outcome measures were age-specific and age-standardized hip fracture rates. The Cochran-Armitage test for linear trend was used to estimate yearly changes in age-specific hip fracture subgroups. Joinpoint regression analysis identified points at which a statistically significant change over time occurred in the linear slope of the trends in hip fracture rates. Over the 21 years of observation, 570,872 cases of hospitalization for hip fractures were identified. A progressive decrease in age-specific hip fracture rates occurred over time among both males (25.0%) and females (31.8%) (P < 0.001 for both): Age-adjusted hip fracture rates among females decreased from 118.6 per 100,000 person-years (95% confidence interval [CI], 115.9-121.4) in 1985 to 80.9 (95% CI, 79.2-82.6) in 2005. Similarly, the age-adjusted hip fracture rates for males decreased from 68.2 per 100,000 person-years (95% CI, 65.6-70.8) to 51.1 (95% CI, 49.4-52.7). Among males and females, joinpoint regression analysis identified a change in the linear slope around 1996. During the early part of the study (1985-1996), the average percentage decrease per year in hip fracture rates was 1.2% (95% CI, 1.0%-1.3%) whereas during the later part of the study (1996-2005), the decrease was 2.4% (95% CI, 2.1%-2.6%) per year from 1996 to 2005 (P < 0.001 for difference in slopes in both time periods). Large changes occurred among both females and males with greater slope reductions after 1996 (P < 0.001 for difference in slopes for both). These findings demonstrate significant progressive decreases in age-standardized rates of hip fracture between 1985 and 2005 and show a more rapid decline in rates in the second half of the study period. The factors contributing to the earlier reduction in hip fracture at a time when there was no widespread diagnostic testing or modern drug therapy are unknown.