Design of the POSSIBLE US™ Study: Postmenopausal women's compliance and persistence with osteoporosis medications

Failure to take prescribed medication is common. The POSSIBLE US™ study is evaluating the impact of physician and patient characteristics on patient-reported compliance and persistence with osteoporosis medications. We report our study design and the baseline characteristics of 4,994 postmenopausal women recruited from primary care physician offices in 33 states. Introduction: The Prospective Observational Scientific Study Investigating Bone Loss Experience (POSSIBLE US™) is a longitudinal cohort study of osteoporosis therapy in primary care. Methods: Between 2004 and 2007, 134 physicians (in 33 states) enrolled postmenopausal women initiating, changing, or continuing osteoporosis medications. After completing a baseline questionnaire, participants will provide data semi-annually for up to 3 years through 2008. Physicians provide patient data at baseline and routine follow-up visits. Participants from 23 sites also signed a release regarding administrative claims data for economic analyses and validation of self-reported data. Baseline results: Four thousand nine hundred and ninety-four evaluable women were recruited from internal medicine (n∈=∈1,784), family practice (n∈=∈1,556), obstetrics/gynecology (n∈=∈1,556), and from one rheumatology practice (n∈=∈98). Mean participant age was 64.3 years (SD∈=∈9.97); 89% were Caucasian; 59% had some college education. Sixty-three percent used a single osteoporosis agent, usually a bisphosphonate. For monotherapy patients, concordance between clinic- and patient-reported medication use was lowest for patients prescribed estrogen therapy (70%) or calcium/vitamin D (72%). Obstetrician/gynecologists enrolled younger women, who were more likely to use estrogen therapy than patients enrolled by other physicians. The 934 women (19%) prescribed only calcium/vitamin D were younger than women prescribed pharmacologic therapy. Conclusions: POSSIBLE US™ provides a unique foundation for evaluating longitudinal use of osteoporosis medications and related outcomes.