Position Statement

Subject: Bone Density Measurement

Presented By: Council on Rheumatologic Care

For Distribution To: Members of the American College of Rheumatology, Medical Societies, Members of Congress, Health Care Organizations/Third Party Carriers, Voluntary Health Organizations, e.g., Arthritis Foundation, National Osteoporosis Foundation

Diseases causing bone loss, such as post-menopausal osteoporosis, corticosteroid-induced osteoporosis, and osteomalacia, are among the conditions affecting the musculoskeletal system which are diagnosed and treated by rheumatologists. In addition, many of the primary rheumatic diseases, especially rheumatoid arthritis, are associated with considerable osteoporosis.

Osteoporosis currently causes 1.5 million fractures annually in the United States at a direct health cost of at least $13 billion.¹ By the year 2020, with no change in current preventive health practices and an aging population, the estimated annual costs for osteoporosis-associated hip fractures are expected to increase to between $31 billion and $62 billion.² The lifetime risk of hip fractures in white women is as great as the combined risk of breast, uterine, and ovarian cancer.³ Within six months of fracture 12 to 20 percent die.³ One-half of the survivors are not able to walk unassisted, and 25 percent are confined to nursing homes for long-term care.³ The most important preventable cause of fractures is low bone mass.

Evidence now exists that currently available therapy — including hormone replacement (HRT) Calcitonin and Bisphosphonate (i.e., Alendronate) not only increases bone density, but substantially decreases fracture risk in osteoporotic women. Further data is emerging that the prophylactic use of HRT and low-dose bisphosphonates (Alendronate) reduces the risk of osteoporosis. The availability of effective therapy and preventive interventions underscores the need of early diagnoses, treatment, and assessment of risks.

Bone mineral density (BMD) is the single most effective measure of future fracture risk. There are a number of different locations where bone density can be measured and a variety of techniques for making those measurements. Peripheral BMD studies (e.g. radius, wrist, heal) remain available. Correlation between peripheral studies of the calcaneus and distal radius with central BMD studies of the hip varies between R values .5-.7. The correlations may be weaker for peri-menopausal younger women than for older women. Thus, the primary usefulness for the peripheral study may be in mass screening or in screening geographic locations where central BMD studies are not available. The appropriateness of peripheral studies in monitoring long term therapy have not been demonstrated.

Central bone density measurements of the spine and hip have the best predictive value for major fracture. Dual Energy X-Ray Absorptiometry is the preferred technique. It is associated with excellent accuracy and precision with relatively minimal radiation exposure. Thus, DEXA is useful for long term monitoring of treatment effects. Precise calibration of equipment and proper patient positioning are essential factors in assuring accuracy in long term monitoring. Therefore, it is reasonable to expect that the DEXA technician and/or the supervising physician have been appropriately certified/trained in DEXA operations/procedures.

A recently passed federal act mandates that women at risk be screened for osteoporosis. The ACR supports this point for view and believes that effective screening measures should be put into place at the state as well as federal level. Currently available DEXA techniques are superb in this regard and screening should be reimbursable by local carriers.

Position:

1. The American College of Rheumatology supports the appropriate use of bone density measurement in the diagnosis of low bone mass and as an assessment of future fracture risk for decision making about therapeutic management. The American College of Rheumatology also supports the use of bone density to monitor bone mass as an assessment of the efficacy of therapy.
   
   
2. The American College of Rheumatology supports the use of bone density measurement in both the diagnosis and the interval monitoring of bone mass in the following groups of patients:
   
   
• women at or after menopause, if the results of the study will influence the decision for estrogen replacement therapy or other potential interventional therapy
  
  
• women who have a family history of osteoporosis; who have early onset of menopause; who have had surgical menopause; or who have low body weight
  
  
• females with aberrations of the menstrual cycle, including female athletes who have ceased to have menstrual periods or have irregular menstrual periods; or females with luteal phase deficiencies
  
  
• individuals with vertebral abnormalities or x-ray evidence of osteopenia
  
  
• individuals receiving long term drug therapy known to predispose to osteoporosis including glucocorticoid therapy, phenytoin therapy, or Heparin therapy
  
  
• individuals who have been on excessive doses of thyroid replacement
  
  
• males with hypogonadism
  
  
• individuals suspected of being estrogen malabsorbers or non-responders
  
  
• individuals with chronic malabsorption or documented calcium malabsorption
  
  
• individuals with asymptomatic primary hyperparathyroidism
  
  
• individuals with a recent fracture of the spine, long bone, hip, or pelvis and the fracture is suspected to be associated with osteoporosis
  
  
3. The ACR supports insurance reimbursement by Medicare and other health insurance reimbursements for bone density measurement for the indications listed in 2. above.

Approval Date : 11/8/97

Ray, N.F., et. al. J. Bone Miner Res, 12:24, 1997

1. Kellie SE. Diagnostic and therapeutic technology assessment. JAMA 267:286-294, 1992
   
   
2. Arthritis, Rheumatic Diseases, and Related Disorders. NIH Publication No. 92-3414:8, 1992