Hip Fracture Incidence: What Is Causing the Decrease?

In a recent study, researchers used data from over 40 years of follow-up from the Framingham Heart Study to examine the incidence of hip fracture and how it has been affected by changes in the rates of known risk factors and time period.

“Age-adjusted hip fracture incidence is decreasing in the US. The decrease has been attributed to osteoporosis treatment, but the cause is unknown,” the researchers wrote.

To explore this further, they examined data from 4918 men and 5634 women who experienced a hip fracture between January 1, 1970 to December 31, 2010. Following adjustment for age, the incidence of hip fracture decreased by 4.4% (95% CI, 6.8%-1.9%) each year during the study period.

The prevalence of various risk factors for hip fracture were also assessed. Prevalence of underweight, obesity, and early menopause were all found to be consistent over the course of the study. However, the prevalence of smoking and heavy drinking decreased from 38% to 15% and 7.0% to 4.5%, respectively, over the study period.

“The decrease in the hip fracture incidence that we observed over a long follow-up in large numbers of men and women may not be explained by better preventive treatment. Rather, it appears that birth cohort effects and improvement in lifestyle factors, particularly reduction in smoking, were prominent factors in the decrease in hip fracture rates over the 4 decades of our study. To reduce the hip fracture burden, treatment of osteoporosis is important as are public health interventions to reduce smoking and heavy drinking,” the researchers concluded.

—Michael Potts

Reference:

Swayambunathan J, Dasgupta A, Rosenberg P, et al. Incidence of hip fracture over 4 decades in the Framingham Heart Study. Published online July 27, 2020. JAMA Intern Med. doi:10.1001/jamainternmed.2020.2975.