Retrospective evaluation of persistence in osteoporosis therapy with oral bisphosphonates in Italy: the TOBI study

Abstract

The patients’ persistence with osteoporosis treatments is low. This retrospective, multicenter survey showed that almost 30% of osteoporotic patients discontinued the treatment within the first 6 months and that those taking drinkable bisphosphonates were less likely to interrupt the therapy; instead, the use of generic bisphosphonates was associated to a more precocious interruption. Purpose: Low persistence with osteoporosis medications is associated with higher fracture risk. This study aimed to assess the persistence to treatment with oral bisphosphonates among Italian osteoporotic patients under treatment for at least 6 months and to evaluate whether the different oral formulations of bisphosphonates may influence the interruption of the therapy. Methods: 723 consecutive osteoporotic patients, aged 50 years or over, referred as outpatients for a follow-up visit after receiving a prescription of an oral bisphosphonate for the first time for at least 6 months were enrolled in this retrospective, multicenter survey carried out under conditions of usual clinical practice. All the patients enrolled were submitted to a standardized interview. Results: 191 patients turned out to have discontinued treatment (28.7%), the more common causes for interruption being the adverse events (43.9%), fear of adverse events (23.3%) and perceived absence of efficacy of the treatment (15.8%). The osteoporotic patients taking drinkable bisphosphonate or on treatment with aromatase inhibitors or under the age of 70 years were less likely to interrupt the treatment. However, these associations were no longer significant when the pharmaceutical formulation (generic vs branded) was included into the multivariate logistic regression model. Conclusion: This study suggests that the new drinkable formulations of bisphosphonates could be an interesting option able to reduce upper GI adverse events, thus increasing persistence; whereas the generic formulations of bisphosphonates were associated to a premature discontinuation.