The clinical diagnosis of osteoporosis: a position statement from the National Bone Health Alliance Working Group

Osteoporosis has been characterized as a skeletal disorder of reduced bone strength that leads to an increased risk for fracture, typically in the setting of low trauma such as a fall from standing height. In the USA today, the standard criterion for defining and diagnosing osteoporosis and applying the ICD-9 code 733.0 is the finding of a T-score of ≤ −2.5 at the lumbar spine, femur neck, or total hip by bone mineral density (BMD) testing [1]. As T-scores decrease, the relative risk for fracture increases. This principle makes the T-score an effective means of identifying those individuals at increased fracture risk and offers a cut point that allows for a diagnosis of osteoporosis. However, it is clear that there are other ways to identify individuals at high fracture risk, including the occurrence of one or more of several types of low-trauma fractures or through the use of fracture risk algorithms such as FRAX. It has been suggested that either of these ways of predicting an increased fracture risk should also enable the use of the diagnostic term osteoporosis [2]. It is the purpose of this paper to make the case that we should formalize this concept and encourage clinicians to use the term osteoporosis when they identify an older patient with an elevated fracture risk determined by any one of these criteria.

Osteoporosis is a public health concern that is associated with over two million fractures per year in the USA [3]. This disease continues to be underdiagnosed, and its management with a variety of treatments, including adequacy of calcium and vitamin D, exercise to improve balance and prevent falls, and pharmacologic therapy as indicated to lower fracture risk, remains suboptimal [3]. The diagnosis of osteoporosis based on a T-score of ≤ −2.5 is and should remain one important way to identify an individual with an increased risk for fracture. Bone density testing is recommended based on age and risk factor status in both men and women by the Surgeon General’s Report on bone health and osteoporosis as well as other guidelines [3‐6], but only a small proportion of older men and women have a BMD test [7]. Many who do receive the test may still not be recognized as having an elevated fracture risk because their scores reflect “osteopenia,” which in some instances does indicate a high risk based on elevated age or prior fracture history or other validated risk factors. Prior fracture affords the highest risk for future fracture [4], yet an older patient with a hip fracture may not be diagnosed as having osteoporosis unless the patient has a BMD test with a T-score of ≤ −2.5, and the majority of hip fracture patients have T-scores that are better than −2.5 [8]. An incident vertebral fracture strongly predicts an increased risk of another vertebral fracture as soon as within the next year [9]. Several other fracture types also increase the risk of future fracture [10], and about half of patients with a hip fracture have already had a previous fracture [11], yet the term osteoporosis is not formally applied unless the BMD T-score is ≤ −2.5. Most fractures occur in people with low bone mass, not “T-score” osteoporosis, because a greater number of people have osteopenia than osteoporosis as defined by BMD [12, 13]. The failure to detect clinical osteoporosis when it is present likely contributes to the current lack of awareness of the consequences of this disease by both clinicians and patients, impacts the reimbursement strategies of payers, influences policy makers in the public health sector by underestimating the number of those at elevated fracture risk, and affects the design of clinical trials of new agents to reduce fracture risk by both pharmaceutical companies and the FDA.

In a position paper published in 2012 [2], a recommendation was made to formally expand the criteria for allowing a diagnosis of osteoporosis to include the presence of certain low-trauma fractures or the determination of an elevated fracture risk using FRAX, without a T-score of −2.5 or lower. A proposal was made to assemble a task force of representatives from the academic and clinical societies that represent the bone field and osteoporosis in particular in the USA, to debate the issue and to reach consensus on the clinical characteristics that would allow and support a clinical diagnosis of osteoporosis in all older individuals who have an elevated risk for fracture.

Under the direction of the National Bone Health Alliance (NBHA), a group of 17 clinicians and clinical scientists were appointed to a Clinical Diagnosis of Osteoporosis Working Group. Three of the members are the three US-based authors of the 2012 position paper [2]; six individuals were appointed by the National Osteoporosis Foundation (NOF), and six were appointed by the American Society for Bone and Mineral Research (ASBMR). One additional member is the representative to the NBHA of the American Academy of Orthopedic Surgeons, and the final member is the Centers for Disease Control Liaison to the NBHA. The committee carried out its work by meeting initially at the 2012 ASBMR annual meeting and, thereafter, through several teleconferences. There was no financial support by any entity for the committee’s work, and full financial disclosure of the members is provided in this document.

The committee set a series of principles in place to be clear about its purpose. First, the population for whom the clinical osteoporosis diagnostic criteria are intended include (a) postmenopausal women and (b) men over the age of 50 in the USA. This population is the same as that included in the NOF Clinician’s Guide [3]. Second, the purpose of expanding the criteria for making a diagnosis is limited to that; no specific treatment recommendations are being suggested as a part of this effort. While the committee agreed that some form of management would likely apply in all persons diagnosed as having osteoporosis by these new criteria (including the use of anti-osteoporosis prescription medication in many but not all cases), the sole purpose of this committee’s deliberations is to expand the criteria by which osteoporosis can be diagnosed. Third, in this report, the terms osteopenia and low bone mass are being used interchangeably and refer to a bone mineral density T-score at the spine, femur neck, or total hip that is < −1.0 and > −2.5. Finally, the fractures we are considering as being diagnostic for osteoporosis are low-trauma or low-energy fractures, such as those occurring in our population from, as an example, a fall from standing height. Fractures resulting from major trauma, e.g., automobile accidents or falls off a roof, are not the fractures we are including in our definition, though in this population, it is still recommended that a bone density test be performed in such individuals to determine if low bone mass or osteoporosis as defined by T-score is present.

The committee recognized that making a diagnosis of a condition is easiest when there are absolute criteria, such as a blood test result above or below a certain cut point or a biopsy of a lesion that has a clear pathological finding. However, often in medicine, we make a diagnosis based on clinical characteristics that reflect a syndrome that requires a diagnosis in order to devise a treatment plan. A solid evidence base coupled with physician judgment in some instances is necessary, and a thoughtful clinician needs to consider whether or not certain clinical characteristics reflect an underlying abnormality and to proceed with management accordingly. Clearly, it is our intent to allow the diagnosis of osteoporosis to be made when there appears to be evidence for believing that an elevated risk for fracture is present but, equally, to afford the opportunity to not use the term if it is not appropriate. Thus, in some instances where our recommendations for making the diagnosis of osteoporosis might apply in some cases but not in others, we have given examples that may be helpful.

We recommend that postmenopausal women and also men over the age of 50 years should be diagnosed as having osteoporosis if it is demonstrated that the individual is at an elevated risk for future fractures. We support the continued use of BMD testing and the finding of a T-score of ≤ −2.5 at the spine or hip as one way to make the diagnosis. We further support the use of the term osteoporosis for individuals in this population who have experienced a low-trauma hip fracture and for those who have osteopenia by BMD who sustain a low-trauma vertebral, proximal humerus, pelvis, or, in some cases, distal forearm fracture. Hip, vertebral, distal radius, and pelvis fractures constitute about two thirds of osteoporosis-associated fractures [22], and proximal humerus fractures are among the four “major osteoporotic fractures” together with hip, spine, and distal forearm fractures in FRAX [15]. Finally, for individuals who have an elevated fracture risk based on FRAX, the term osteoporosis can be used for diagnosis.

We hope to formalize these principles through future interactions with third-party payers as well as with our colleagues in primary care and orthopedics. As the new ICD-10 codes become available in 2014–2015, it is our hope that this new understanding on what osteoporosis represents will allow for its appropriate diagnosis when older individuals are recognized as being at an elevated risk for fracture.