WASHINGTON — Primary care physicians are less likely than specialists to initiate a work-up for secondary causes of bone loss in patients with scans indicating low bone density, despite a recommendation to do so.
That finding emerged from a study presented in poster form during the annual meeting of the North American Menopause Society.
Some patients with scans indicating osteoporosis were premenopausal women who started treatment with a bisphosphonate after their physicians received the scan results. Eventually, however, these patients were diagnosed with vitamin D deficiency, according to Andrea Sikon, M.D., of the Cleveland Clinic Women's Health Center, and her associates.
The study involved a review of 1,114 consecutive dual energy x-ray absorptiometry (DXA) scans performed at the center from July 2002 to August 2003. Of these scans, 712 (64%) were considered indicative of osteopenia (a T score ranging from -1.1 to -2.4), or of osteoporosis (a T score of -2.5 or below), according to World Health Organization criteria.
An evaluation for secondary causes of low bone density was recommended by the interpreter reading the scans in 77 of the 712 women with z scores equal to or less than -1.5.
These 77 women were aged 27-84 years, with a mean of 53 years.
But only 49 (64%) of the 77 women actually had a secondary evaluation as recommended, and laboratory tests were drawn only in 42 (55%) of these women.
Most of the specialists—which included rheumatologists, osteoporosis specialists, and North American Menopause Society-certified women's health specialists—followed up with patients as recommended, compared with less than one-third of primary care physicians, which included general ob.gyns., internists, and family physicians who practiced at the Cleveland Clinic.
Of the 41 women whose DXA scan had been ordered by a specialist, 39 (95%) had a secondary work-up initiated by the physician. But among the 36 whose primary care physician had ordered the DXA scan, only 10 (28%) had a work-up, according to the investigators.
Of the 42 women who had the full work-up, including lab tests, 23 (55%) were diagnosed with vitamin D deficiency, 4 (9%) were diagnosed with primary hyperparathyroidism, and 5 (12%) were diagnosed with premature ovarian insufficiency.
Concluding that specialists were more likely to perform the secondary evaluation, the study authors recommended that vitamin D, 25-hydroxyvitamin D, and parathyroid hormone levels should be drawn on all women with z scores that are at or below -1.5.
In an interview with this newspaper, study investigator Holly L. Thacker, M.D., who is the head of the Cleveland Clinic Women's Health Center, said it is unclear whether the physicians read the entire report or perhaps did not know which secondary work-up to conduct.