Little or no data exist on hip fracture in American Indians, Alaskan Natives

For the past several years, the AAOS has helped focus attention on healthcare disparities among diverse groups. The increasing ethnic diversity of our country requires a variety of strategies to address any inequities in delivering the best orthopaedic care possible to all patients.

It appears, however, that the numerous attempts to reduce disparities in health care are having little impact. According to an article in the Journal of the American Medical Association (March 26, 2008), “despite decades of efforts to raise awareness about disparities and to reduce them, the gaps in some key treatment areas have not budged.”

Hip fracture treatment is one of those key areas where disparities in health care and delivery can have costly consequences, both for individuals and society. Consider the following facts:

• Hip fractures account for 14 percent of all fractures.
• Although hip fractures occur more commonly in women, approximately 25 percent to 30 percent of the 330,000 hip fractures that occur annually in the United States occur in men.
• Hip fractures have high morbidity and mortality, particularly among men.
• Caucasians have borne the brunt of the burden of hip fracture mostly due to osteoporosis.

Expanding hip fracture research
Most past research studies on hip fractures have focused on Caucasian women. The higher mortality rates among men, however, are spurring researchers to include men in more studies. Other ethnic populations, including Asian-Americans, Hispanic-Americans and African-Americans, are also included as subjects in hip fracture and osteoporosis studies. But what about the American Indian/ Alaskan Native (AIAN) population?

According to the U.S. Census Bureau (2008 data), an estimated 4.9 million American Indians and Alaskan Natives live in the United States. Information on hip fracture prevalence among the AIAN population is limited and relies on a few studies conducted during the past 20 years. These studies seem to indicate that disparities exist and that they may be increasing.

A study comparing the incidence of hip fracture in Alaskan Natives (Inuit) during two periods (1979–1989 and 1996–1999) found that the incidence of hip fracture in Inuit women older than 64 years of age was higher than the incidence of hip fracture in white women in the United States in 1979–1989, and had increased further by 1996–1999. Inuit men also had a higher hip fracture incidence than U.S. men in the years 1996–1999.

Hip fracture hospitalization data from 2000 to 2007 are available for various races and ethnicities among persons age 65 years and older in a California database.

Although hospitalization data for AIAN males were unreliable because of the small number of events, the hip fracture hospitalization rate for AIAN females was 209.6 per 100,000 in 2005. This compares to a rate of 897.3 per 100,000 for Caucasian females.

A study investigating the influence of ethnicity and bone mineral density (BMD) on fractures in postmenopausal women may shed some light on the prevalence of low BMD, osteoporosis, and fracture risk in the AIAN population. The study involved a large cohort of 197,848 postmenopausal women from five ethnic groups. Even though AIAN women comprised less than 1 percent of the cohort, they had the highest personal fracture history (15.3 percent). The most common fractures reported were wrist, rib, hip, and spine.

In this study, the relative risk of an osteoporotic fracture for the AIAN population was 0.87, lower than for whites and Hispanic-Americans, but higher than for Asian-Americans and African- Americans. The relative risk for nonwrist fractures showed a similar trend. Furthermore, for all ethnicities in general, this study supported the fact that, within any single ethnic group, fracture risk increases as peripherally measured BMD decreases.

Conclusion
Controlled studies looking at hip fracture in the AIAN population are still in their infancy. Few published studies have analyzed AIAN women and even less information is available on hip fracture in AIAN men. Studies on risk factors for osteoporosis, low BMD, and fracture risk have compared AIAN women to non-Hispanic whites and other ethnic groups. Uncovering the prevalence of osteoporosis, hip fracture rate, and any unique characteristics or comorbidities (such as diet, lifestyle, and effect of latitude) that affect bone metabolism and fracture risk would enhance cultural competency within this population.

Laura M. Gehrig, MD, is the Ruth Jackson Orthopaedic Society liaison to the AAOS Diversity Advisory Board. She can be reached at laura.gehrig@gmail.com

References:

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