Hip fracture risk in older US adults by treatment eligibility status based on new National Osteoporosis Foundation guidance

Summary: This analysis of National Health and Nutrition Examination Survey III data found a significant risk of incident hip fracture in adults aged 65 years and older who are candidates for treatment to lower fracture risk, according to the new National Osteoporosis Foundation Clinician's Guide. Introduction: The relationship between treatment eligibility by the new National Osteoporosis Foundation (NOF) Guide to the Prevention and Treatment of Osteoporosis and the risk of subsequent hip fracture is unknown. Methods: The study sample consisted of 3,208 men and women ages 65 years and older who were examined in the third National Health and Nutrition Examination Survey (NHANES III, 1988-1994), a nationally representative survey. Risk factors used to define treatment eligibility at baseline were measured in NHANES III or were simulated using World Health Organization study cohorts. Incident hip fractures were ascertained using linked mortality and Medicare records that were obtained for NHANES III participants through December 31, 2000. Cox proportional hazards models were used to estimate the relative risk (RR) of hip fracture by treatment eligibility status. Results: The RR for subsequent hip fracture was 4.9 (95% CI 3.30, 7.94) in treatment-eligible vs treatment-ineligible persons. The increased risk for treatment-eligible persons remained statistically significant when examined by sex or age: RR _men=5.5 (2.6, 11.4) and RR _women=4.3 (2.2, 8.4); RR _{65-79 y}=4.8 (2.6, 8.7) and RR _{80+ y}=4.6 (2.1, 10.1). Conclusions: Treatment-eligible persons were about five times more likely to experience a subsequent hip fracture than the non-eligible persons. The new NOF guidelines appear to predict future hip fracture risk equally in men as in women, and fracture risk prediction did not appear to diminish with age.