The impact of fragility fracture and approaches to osteoporosis risk assessment worldwide

Abstract

Osteoporosis constitutes a major public health problem, through its association with age-related fractures, particularly of the hip, vertebrae, distal forearm and humerus. Substantial geographic variation has been noted in the incidence of osteoporotic fractures worldwide, with Western populations (North America, Europe and Oceania), reporting increases in hip fracture throughout the second half of the 20th century, with a stabilisation or decline in the last two decades. In developing populations however, particularly in Asia, the rates of osteoporotic fracture appears to be increasing. The massive global burden consequent to osteoporosis means that fracture risk assessment should be a high priority among health measures considered by policy makers. The WHO operational definition of osteoporosis, based on a measurement of bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA), has been used globally since the mid-1990s. However, although this definition identifies those at greatest individual risk of fracture, in the population overall a greater total number of fractures occur in individuals with BMD values above the threshold for osteoporosis diagnosis. A number of web-based tools to enable the inclusion of clinical risk factors, with or without BMD, in fracture prediction algorithms have been developed to improve the identification of individuals at high fracture risk, the most commonly used globally being FRAX®. Access to DXA, osteoporosis risk assessment, case finding and treatment varies worldwide, but despite such advances studies indicate that a minority of men and women at high fracture risk receive treatment. Importantly, research is ongoing to demonstrate the clinical efficacy and cost-effectiveness of osteoporosis case finding and risk assessment strategies worldwide. The huge burden caused by osteoporosis related fractures to individuals, healthcare systems and societies should provide a clear impetus for the progression of such approaches.

Keywords: Assessment; Epidemiology; Geography; High fracture risk; Osteoporosis.

Figure 1

Hip fracture rates for men and women combined in different countries of the world categorised by risk, countries are coded red (annual incidence >250/100,000), orange (150-250/100,000) or green (<150/100,000) where estimates are available. (Reproduced with permission from Kanis et al, Osteoporosis International 2012 [9])

Figure 2

Ten year probability of major fracture (in percent) in men and women aged 65 years with a prior fragiltity fracture and no other clinical risk factors, with a BMI of 24kg/m² at the threshold of osteoporosis as judged by BMD at the femoral neck (i.e. T-score -2.5). (Reproduced with permission from Kanis et al, Osteoporosis International 2012[9])

Figure 3

Incidence of hip / femur and fragility fractures by ethnicity in men and women aged over 50 years in the UK (Data from UK Clinical Practice Research Datalink, 1988-2012) (adapted with permission from Curtis et al Bone 2016[18])

Figure 4

Trends in hip fracture worldwide over time: annual change in age and sex-adjusted hip fracture incidence (Reproduced with permission from Cooper et al, Osteoporosis International 2011 [33])

Figure 5

Number of men and women at high fracture risk in 2040 relative to 2010, by world region. (With permission from Oden et al, Osteoporosis International 2015 [44]).