Oakland, CA—The many bisphosphonate (BP) prescriptions filled by pharmacists are now likely to be even more appropriate than in the past.

A presentation at ENDO 2019, the Endocrine Society’s annual meeting in New Orleans, points out that more of the prescriptions are written for older women who have osteoporosis, not just osteopenia.

“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,” explained senior study author Joan Lo, MD, of Kaiser Permanente Northern California Division of Research in Oakland, California.

“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,” Lo added.

Background information in the study notes that initial guidelines focused on early primary prevention of fracture for postmenopausal women using a bone mineral density T-score -2.0 or lower, regardless of age (T-score <-1.5 with risk factors). In 2008, however, national guidelines focused treatment on osteoporosis (T-score <-2.5) or osteopenia (-1 >T-score >-2.5) with high fracture risk based on the FRAX risk-assessment tool.

The study team decided to examine whether there has been a shift in the characteristics of women initiating BP therapy for primary prevention—i.e., no previous fracture—over time from 2002 to 2013.

To do that, the researchers used data from an integrated healthcare delivery system in northern California to identify women who were aged 50 to 79 years, initiated oral BP in 2002-2013, and had bone mineral density measured within the 2 previous years. Ultimately, the study included 28,495 women with a mean age of 66 years; 56% were non-Hispanic white, 27% Asian, and all others,17%.

Results indicate that, for each year from 2002-2013, the proportions of women aged 65 years and younger declined as the proportions older than age 65 years increased among those initiating BP. By age decade, the proportion aged 50 to 59 years declined from 31% to 12%, while the proportion aged 60 to 69 years and 70 to 79 years increased from 39% to 54% and 29% to 34%, respectively, from 2002-2013, according to the study.

By 2013, the researchers found, the predominant age group initiating BP was ages 60 to 69 years—54% overall, 51% in whites, and 63% in Asians. At the same time, the percentage of women initiating BP who had osteoporosis progressively increased from 62% in 2002 to 79% in 2013. Only among the cohort of older women age 70-79 years was there no significant change over time: 71% in 2002-2007 versus 69% in 2008-2013.

“Over time, there has been a remarkable shift in the type of woman initiating BP for primary prevention, from younger to older and from those with osteopenia to osteoporosis,” the study authors write. “By 2013, over half of the women initiating BP were 60-69y, and compared to 2002, there was a 27% higher prevalence of osteoporosis among women starting BP.”

“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 added.

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