Tohoku J. Exp. Med., 2021 September, 255(2)

Adherence to Daily, Weekly, and Monthly Dosing Regimens of Bisphosphonates for Osteoporosis Treatment in Postmenopausal Women in Japan: A Retrospective Study Using Claims Data

Yuki Kosaka,¹ Takehiro Sugiyama,² Konan Hara³ and Yasuki Kobayashi³

¹Biometrics Research Laboratories, NEC Corporation, Kawasaki, Kanagawa, Japan
²Diabetes and Metabolism Information Center, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
³Department of Public Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan

Poor medication adherence of osteoporosis patients is a major global medical problem because of its negative impact on health outcomes and quality of life. The aim of this study was to evaluate how differences in dosing regimens influence adherence to oral bisphosphonates using data from a large health insurance provider in Japan. This was a retrospective observational study using claims data obtained between October 2012 and January 2018, from the community-based National Health Insurance program of a large city in Japan. The data included in the analysis were obtained from women 60 to 74 years old whose oral bisphosphonate prescription was detected between April 2013 and February 2017. Treatment adherence was monitored from the initial prescription for one year, i.e., up to January 2018. Primary comparisons among the daily-dosing, weekly-dosing, and monthly-dosing groups were based on the mean medication possession ratio (MPR). Data from a total of 3,958 patients were analyzed. The numbers of patients aged 60-64, 65-69, and 70-74 were 425, 1,400, and 2,133, respectively. The highest mean MPR was 69.4% for the monthly-dosing of bisphosphonates, followed by the weekly-dosing at 63.5%, and daily-dosing at 57.2%. Using the Kruskal-Wallis test with Dunn-Bonferroni correction, there were significant differences in mean MPR for daily versus weekly (p < 0.01), daily versus monthly (p < 0.001), and weekly versus monthly dosing regimens (p < 0.05). These results suggest significantly more patients adhere to a monthly or weekly regimen of bisphosphonates in the treatment of osteoporosis than to a daily regimen.

Keywords —— adherence; bisphosphonates; claims data; dosing regimens; Japan

© 2021 Tohoku University Medical Press

===============================

Tohoku J. Exp. Med 2021, 255, 147-155.

Correspondence: Yasuki Kobayashi, Department of Public Health, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bukyo-ku, Tokyo 113-0033, Japan.

e-mail: yasukik@m.u-tokyo.ac.jp