BEATRIS Study: A Study of Adherence to Bonviva (Ibandronate) Once Monthly in Women With Post-Menopausal Osteoporosis

Inclusion Criteria: * ambulatory post-menopausal women with osteoporosis; * 55-85 years of age; * eligible for bisphosphonate treatment; * naive to bisphosphonate therapy, or lapsed users (last bisphosphonate intake \> 6 months ago). Exclusion Criteria: * inability to stand or sit in an upright position for at least 60 minutes; * inability to swallow a tablet whole; * hypersensitivity to bisphosphonates; * administration of any drug, or presence of active disease, known to influence bone metabolism; * uncorrected hypocalcemia or other bone disturbances of bone and mineral metabolism; * history of major upper gastrointestinal disease.