Investigation of Bisphosphonate Therapy for Osteoporosis: A Single-Center Cross-Sectional Study.

Background: This study aimed to examine the management of bisphosphonate (BP) therapy for osteoporosis in Japan, focusing on treatment duration, dual-energy X-ray absorptiometry (DXA) assessment status, therapy despite renal impairment, and history of atypical femoral fracture (AFF). Methods: This single-center, cross-sectional study included 117 women inpatients aged ≥ 65 years admitted to the Department of General Medicine at Nerima Hikarigaoka Hospital between October 2022 and September 2025 while receiving BP therapy. The primary outcome was the prevalence of ultra-long-term therapy (≥ 10 years oral or ≥ 6 years intravenous). Secondary outcomes included long-term therapy (≥ 5 years oral or ≥ 3 years intravenous), unknown treatment duration, inadequate DXA assessment, therapy despite renal impairment (serum creatinine ≥ 1.5 mg/dL), and AFF history. Results: The mean age was 84.3 ± 7.1 years. Ultra-long-term therapy occurred in 5.1% of patients, long-term therapy in 23.1%, unknown treatment duration in 29.9%, and inadequate DXA assessment in 49.6%. Therapy despite renal impairment was noted in 6.8%, and one patient (0.8%) had AFF. Unknown treatment duration and inadequate DXA assessment were significantly more common in nonorthopedic care and in facility- or home-based settings ( Conclusions: Among older women in Japan, ultra-long-term BP therapy was rare; however, nearly half lacked adequate assessment of treatment duration or documented DXA evaluation. These findings reveal shortcomings in long-term osteoporosis management, particularly in nonorthopedic and facility- or home-based care settings. Standardized reassessment, appropriate DXA evaluation, and improved information sharing across care transitions are essential to optimize treatment quality and safety in an aging population.