Adherence to bisphosphonate therapy in postmenopausal osteoporotic women

Osteoporosis is a metabolic bone disease caused by a decrease in the bone mineral density. It is a major public health threat as it weakens bones, especially those in the wrist, spine, or hip, and causes them to break easily.

The study aimed to find how strictly postmenopausal women with osteoporosis adhere to a long-term therapy with bisphosphonates.

The study was conducted over a 24-month period. It included a total of 341 randomized patients with postmenopausal osteoporosis; the diagnosis was made on the basis of clinical and radiological evidence and a DXA T-score of the axial skeleton and the left hip less than -2.5 SD. Therapy included per os administration of alendonate 70 mg once a week or 50 mg of ibandronate once a month.

The patient medication persistence at the end of month 12 was 86.80%, and at the end of month 24 month - 58.94%. The medication possession ratio (MPR) in the bisphosphonate therapy at 6, 12, 18, and 24 months varied from 0.93 to 1.00. This suggests that there was a very good patient medication adherence of the study subjects to the 24-month treatment with bisphosphonates. The patient medication persistence dropped significantly at the end of month 12.

Compliance of patients with antiresorptive therapy depends on the specific socio-economic conditions and the attending physician's behaviour. Very rarely, treatment is discontinued because of adverse effects exerted by the drugs or because patients may not be convinced that they have osteoporosis.