Compliance, persistence, and preference outcomes of postmenopausal osteoporotic women receiving a flexible or fixed regimen of daily risedronate: A multicenter, prospective, parallel group study.

Objective: The aim of this study was to examine the level of compliance and persistence in patients with postmenopausal osteoporosis (OP) receiving daily risedronate (5 mg) with either fixed dosing of three different timing regimens (A: before breakfast; B: in-between meals; C: before bedtime) or with flexible dosing and the effect on urinary N-terminal telopeptide of Type 1 collagen (NTX-1).
Methods: The study included 448 patients with postmenopausal OP. Patients were randomly assigned into six treatment groups each with a permutation of the treatment sequence (ABC, BCA, etc.) in the crossover phase (3 x 1 week) and randomized to 23 weeks of either the daily flexible (either regimen A, B or C) or fixed timing (only regimen A, B, or C) in the patient's preference phase. Urinary NTX-1 was tested.
Results: A total of 433 patients participated in the patient's preference phase (49.7% preferred flexible and 50.3% fixed timing). There was no significant difference between the proportion of responders who were both compliant and persistent in the flexible (54.4%) and fixed regimens (53.7%) (p=0.8803). A significant difference between the flexible and fixed regimens was seen in persistence in favor of the flexible regimen (p=0.0306). There was no significant difference between the flexible and fixed regimens in terms of compliance (p=0.4611). Change in urinary NTX-1 did not show any difference between the two regimens. At the final visit, 51% of patients in the flexible and 55% in the fixed regimen group considered the used risedronate regimen as excellent or very good (p=0.1440).
Conclusion: A flexible dosing with daily risedronate appears be a valuable option in terms of compliance and persistence for patients with postmenopausal OP.