Initiation of osteoporosis treatment after bone mineral density testing

The aim of the study was to describe initiation of osteoporosis drug therap y after bone mineral density (BMD) testing and to determine any association with BMD test results obtained, physician factors, or both. The setting wa s the Kaiser Foundation Health Plan (KFHP), a large health maintenance orga nization (HMO) in Northern California. Data were collected from bone densit ometry centers at four KFHP medical centers sites in Sacramento, San Rafael , Fresno, and Oakland. We identified 17 290 women aged greater than or equa l to 45 years who had BMD testing between January 1, 1997 and June 30, 1999 . After excluding those for whom any osteoporosis drugs were prescribed in the year before testing, 8020 women were available for analysis. Using logi stic regression, we examined the association between BMD diagnosis (i.e., o steoporosis or osteopenia versus normal) and initiation of drug therapy for osteoporosis (including hormone replacement therapy (HRT), alendronate, et idronate, raloxifene and calcitonin) within 6 months after the test. Among the 8020 women, 1934 (24%) filled a prescription for an osteoporosis drug w ithin 6 months after BMD testing. Compared with women who had a normal BMD test result, women diagnosed with osteopenia were nearly 4 times more likel y (OR = 3.7; CI = 3.0-4.4), and women diagnosed with osteoporosis were 15 t imes more likely (OR = 15.0; CI = 12.5-18.1), to fill a prescription for an osteoporosis drug within 6 months after BMD testing. Women with high expos ure to corticosteroid agents were twice as likely (OR = 2.1; CI = 1.7-2.7) to start osteoporosis drug therapy compared with women who were not similar ly exposed; women diagnosed with recent osteoporotic fractures were 50% mor e likely (OR = 1.5; CI = 1.2-1.9) to begin therapy than women without such fractures. Despite the strong association between BMD and initiating treatm ent, nearly half the osteoporotic women did not initiate treatment. In addi tion, we found that age strongly influenced choice of osteoporotic drug. Co mpared with osteoporotic women aged 45-54 years, women aged 55-64 years who started drug therapy were 40% more likely (OR = 1.4; CI = 1.0-2.2) and wom en aged greater than or equal to 65 years were twice as likely (OR = 2.0; C I = 1.4-2.8) to start non-HRT drugs. BMD test results indicating osteoporos is were thus strongly associated with increased likelihood of beginning dru g therapy, and half of such women initiated therapy. Drug initiation was al so associated with other factors, including age, use of corticosteroid agen ts, recent fracture, and physician characteristics. However, these factors showed much weaker associations than those found for BMD. Health care provi ders must consider whether test results will influence treatment decisions, and our data indicate that results of BMD testing do influence management decisions regarding osteoporosis drug use for women.