The U.S. Preventive Services Task Force commissioned a systematic evidence review of 168 fair-good quality articles to examine newer evidence on screening for and treatment of osteoporotic fracture in women and men and update its 2011 guideline. For postmenopausal women older than 65 years and those younger than 65 years with increased risk of osteoporosis, USPSTF found convincing evidence that screening can detect osteoporosis and that treatment can provide at least a moderate benefit in preventing fractures (grade B). For men, they report inadequate evidence on the benefits and harms of screening for osteoporosis to reduce the risk of fractures (I statement).
Dr. Neil Skolnik (left) and Dr. Aarisha Shrestha
Importance
Osteoporosis leads to increased bone fragility and risk of fractures, specifically hip fractures, that are associated with limitations in ambulation, chronic pain, disability and loss of independence, and decreased quality of life: 21%-30% of those who suffer hip fractures die within 1 year. Osteoporosis is usually asymptomatic until a fracture occurs, thus preventing fractures is the main goal of an osteoporosis screening strategy. With the increasing life expectancy of the U.S. population, the potential preventable burden is likely to increase in future years.
Screening tests
The most commonly used test is central dual energy x-ray absorptiometry (DXA), which provides measurement of bone mineral density (BMD) of the hip and lumbar spine. Most treatment guidelines already use central DXA BMD to define osteoporosis and the threshold at which to start drug therapies for prevention. Other lower-cost and more accessible alternatives include peripheral DXA, which measures BMD at lower forearm and heel, and quantitative ultrasound (QUS), which also evaluates peripheral sites like the calcaneus. QUS does not measure BMD. USPSTF found that the harms associated with screening were small (mainly radiation exposure from DXA and opportunity costs).
Population and risk assessment
The review included adults older than 40 years of age, mostly postmenopausal women, without a history of previous low-trauma fractures, without conditions or medications that may cause secondary osteoporosis, and without increased risk of falls.
Patients at increased risk of osteoporotic fractures include those with parental history of hip fractures, low body weight, excessive alcohol consumption, and smokers. For postmenopausal women younger than 65 years of age with at least one risk factor, a reasonable approach to determine who should be screened with BMD is to use one of the various clinical risk assessment tools available. The most frequently studied tools in women are the Osteoporosis Risk Assessment Instrument (ORAI), Osteoporosis Index of Risk (OSIRIS), Osteoporosis Self-Assessment Tool (OST), and Simple Calculated Osteoporosis Risk Estimation (SCORE). The Fracture Risk Assessment (FRAX) tool calculates the 10-year risk of a major osteoporotic fracture (MOF) using clinical risk factors. For example, one approach is to perform BMD in women younger than 65 years with a FRAX risk greater than 8.4% (the FRAX risk of a 65-year-old woman of mean height and weight without major risk factors).
In men, the prevalence of osteoporosis (4.3%) is generally lower than in women (15.4%). In the absence of other risk factors, it is not till age 80 that the prevalence of osteoporosis in white men starts to reach that of a 65-year-old white woman. While men have similar risk factors as women described above, men with hypogonadism, history of cerebrovascular accident, and history of diabetes are also at increased risk of fracture.