Adherence and persistence associated with the pharmacologic treatment of osteoporosis in a managed care setting

The effectiveness of chronic therapies can be compromised by poor adherence and persistence.

Investigators identified a continuously benefit-eligible cohort of women from a large, geographically diverse, national managed care plan who were newly diagnosed and treated for osteoporosis with alendronate, risedronate, or raloxifene. Drug utilization parameters were evaluated over a 12-month follow-up period for the study population. Adherence was assessed using a medication possession ratio calculated as total days of therapy for medication dispensed/365 days of study follow-up. Persistence was defined as continuous therapy on the same drug for each month over the entire study period. Adherence and persistence were also evaluated for all three study agents in women > or = 65 years of age.

In the study cohort (N = 10,566), 12-month adherence/ persistence rates were alendronate 61%/21%, risedronate 58%/19%, and raloxifene 54%/16%. Rates in women > or = 65 years were similar to those in the entire study cohort. Weekly bisphosphonate users had slightly higher 12-month adherence (63% versus 54%, P < 0.05) and persistence (22% versus 19%, P = NS) rates than did daily users, independent of agent.

Chronic oral-dosed osteoporosis therapies are associated with poor adherence and persistence, regardless of age or dosing regimen. Drug therapies and patient management approaches associated with improved adherence and persistence could improve the likelihood of achieving the therapeutic benefits observed in rigorously controlled clinical trials.