Bisphosphonates increasingly prescribed to the women most likely to benefit

"Bisphosphonate drugs have been first-line therapy for osteoporosis and fracture prevention for more than 20 years; however, osteoporosis care has changed over the past decade. Instead of treating younger, healthier women at low risk for fracture, the medical community now focuses on treating older women and those with bone density and other factors that indicate high risk for future fracture," said senior study author Joan Lo, M.D., of Kaiser Permanente Northern California Division of Research in Oakland, Calif.

"These findings reflect the success of regional initiatives targeting these potent therapies to those who will benefit the most. In response to national guidelines and quality metrics introduced in 2008, we are doing a better job of giving more appropriate drug treatment to women who are most likely to benefit while avoiding excess treatment of women at low risk for fracture," she said.

To investigate whether the characteristics of women who began BP therapy changed over a recent 12-year period, Lo and her colleagues at Kaiser Permanente reviewed the records of women in the integrated Northern California health care system, which serves 4.3 million members.

The research team included 28,495 female members in their study: the women ranged in age from 50 to 79 years, initiated oral BP therapy between 2002 and 2013, underwent a bone mineral density (BMD) test within the past two years, had no fracture history (except for head, fingers, or toes), and did not have advanced kidney disease or metastatic cancer.

For each of the 12 years, the percentage of younger women fell while the percentage of older women increased; over the years, the percentage of women initiating BP treatment who were between 50 and 59 years of age dropped (31 percent to 12 percent), while the percentage of women between 60 and 69 (39 percent to 54 percent) and 70 and 79 (29 percent to 34 percent) rose.

Among women starting BP treatment, the percentage with osteopenia fell, while the percentage with osteoporosis at the time of starting treatment expanded from 62 percent in 2002 to 79 percent in 2013.

The overall percentage of osteoporosis among white women was 65 percent, increasing from 58 percent in 2002 to 71 percent in 2013. Among Asian women, the overall percentage of osteoporosis was 82 percent, increasing from 74 percent to 95 percent over the same period.

"Approximately 13 percent to 15 percent of older women in the health plan were Asian compared to 27 percent of our study population, which suggests that Asians may be more likely to begin bisphosphonate treatment for primary prevention," Lo said.