Expected change: a new concept for monitoring patients on oral bisphosphonates

It is essential to closely monitor the response to oral bisphosphonate therapy for osteoporosis, as many patients are nonadherent. The conventional approach is to monitor whether changes in BMD or bone turnover markers exceed the least significant change. That approach assumed that if a patient were not receiving a treatment, there would be no change in the BMD. We propose an alternative approach, that of expected change. We define this expected change as the change in bone mineral density (BMD) (at 24 months) or bone turnover markers (at three months) that is exceeded in 90% of patients who are adherent with oral bisphosphonate therapy. We studied 108 postmenopausal women (age