OBJECTIVES: PMO (prevalence: 7-30%) increases the risk of fractures, reduces life quality and expectancy, leads to loss of employment and creates significant healthcare costs. Poor clinical outcomes have been associated with lack of adherence to treatment. This analysis assesses PMO patient adherence to bisphosphonate therapy in Germany. METHODS: Applying a systematic review of literature utilizing German-based data, we identified and analyzed nine studies assessing adherence to oral bisphosphonates published between 2005 and 2009. Our analysis considered persistence and compliance associated with daily and weekly dosing regimens. Compliance was defined as Medication Possession Ratio (MPR) ³80%. RESULTS: Only 10% of PMO patients in Germany are currently treated with bisphosphonates. Between 31.3% and 46.0% of patients discontinued therapy after the first prescription. Studies showed poor persistence to bisphosphonate therapy during the first year (43.2%). The persistence during the first year was lower with daily dosing compared with weekly dosing regimen (27.8-42% vs. 46.5-57%, respectively). Patients’ compliance varied from 41.7-58.2% over the first year. Reasons identified for poor persistence and compliance included inconvenience and frequency of administration, imperceptible efficacy, and lack of patient education on the need for the medication. Non-compliance was primarily due to side effects. Overall, studies concluded that poor adherence leads to greater economic burden due to higher fracture rates and increased hospitalizations. CONCLUSIONS: A significant proportion of PMO patients discontinued and/or did not comply with therapy during the first year, likely due to dosage inconvenience and frequency, and side effects. There is a need for treatments that patients consider more convenient and are associated with fewer side effects.