Timeliness of antiresorptive consolidation after anabolic therapy for primary fracture prevention: A US cohort study

CONTEXT: Osteoanabolic therapy for osteoporosis should be followed by antiresorptive treatment ("consolidation") to preserve bone mass. Although osteoanabolic therapy is increasingly endorsed for primary fracture prevention, real-world implementation of consolidation remains unknown. OBJECTIVE: To assess patterns and predictors of timely consolidation after osteoanabolic therapy for primary fracture prevention. METHODS: We conducted a retrospective cohort study using US commercial, Medicare Advantage, and traditional Medicare claims data. Adults aged ≥50 years who initiated romosozumab, teriparatide, or abaloparatide between 2011 and 2022 were included. The primary outcome was timely consolidation, defined as initiation of an antiresorptive medication within 3 months after osteoanabolic therapy. Secondary outcomes included delayed consolidation (initiation >3 months after completion), osteoanabolic restart following a treatment gap, and no consolidation therapy. We further distinguished participants who completed the full osteoanabolic course, defined as ≥12 months for romosozumab and ≥18 months for teriparatide or abaloparatide. Multivariable logistic regression models were used to identify predictors of consolidation patterns. RESULTS: Among 15 389 patients (mean age 70.6 years; 89% women; 85% White), 30% completed osteoanabolic therapy (median, 12.9 months for romosozumab; 23.4 months for teriparatide/abaloparatide). Overall, 25% had timely consolidation, 24% delayed consolidation, 12% restarted osteoanabolics, and 40% had no consolidation; only 12% completed therapy with timely consolidation. Timely consolidation was more likely with endocrinology (OR 1.31; 95% CI, 1.17-1.48) or rheumatology (OR 1.45; 1.30-1.62) vs primary care, and less likely among patients aged 50-64 years (OR 0.67; 0.58-0.77) vs 65-74, those enrolled in Medicare Advantage (OR 0.85; 0.74-0.98) vs traditional Medicare, or those recently hospitalized (OR 0.88; 0.80-0.97). Odds increased over time (OR 4.27; 3.63-5.05 for 2021 vs 2011 starts). CONCLUSION: Only 1 in 4 patients received timely consolidation therapy after osteoanabolic treatment, and 1 in 8 completed the full sequence. Strategies to improve consolidation in primary fracture prevention are needed.