Mignot MA, et al. – The clinicians wished to assess the fracture risk in postmenopausal women with osteoporosis after discontinuing bisphosphonate (BP) treatment (BP “drug holiday”). They reported a 40% higher risk of new clinical fractures in subjects who discontinued bisphosphonate treatment.

Methods

• This study was conducted at Lille University Hospital (LUH) on postmenopausal women with osteoporosis who had taken a “drug holiday” or continued treatment after first-line BP therapy (3 to 5 years).
• The occurrence of new clinical fractures during follow-up was also explored. 
• Cox proportional hazards models were used to investigate the relationships between BP “drug holiday” and the occurrence of clinical fractures, while controlling for confounding factors.
• With Kaplan-Meier curves and log-rank tests, survival without new clinical fractures was evaluated.

Results

• This study included 183 women (mean age: 61.8 years; SD: 8.7) who had previously undergone BP treatment for 3 to 5 years.
• The patients had received alendronate (n = 81), risedronate (n = 73), zoledronic acid (n = 20), and ibandronate (n = 9). In 166 patients (“drug holiday” group: n = 31; continuous-treatment group: n = 135), follow-up ranged from 6 to 36 months (mean duration: 31.8 months; SD: 8.2).
• The incidences of new clinical fractures during follow-up were 16.1% (5/31) and 11.9% (16/135).
• After full adjustment, the hazard ratio of new clinical fractures among “drug holiday” patients was 1.40 (95% CI: 1.12–1.60; p = 0.0095).