7474 Demographic Patterns In Early Vertebral Fracture Diagnoses Among Women After Initiation Of Bisphosphonate Therapy

Abstract Disclosure: J.C. Lo: None. G.H. Tabada: None. M. Chandra: None. L.D. Carbone: None. T.C. Tan: None. J. Yang: None. E. Garcia: None. Introduction: Vertebral fractures (VFX) are a major osteoporotic fracture that identify women at high risk for subsequent fracture. However, less is known about demographic patterns in VFX diagnoses among women initiating osteoporosis therapy, including prior and subsequent VFX diagnoses. In this study, we examined racial and ethnic variation in VFX diagnoses among older women who initiated oral BP therapy in a large healthcare system. Methods: The study cohort included women aged 65-85y who initiated oral bisphosphonate (BP) therapy in 2008-2017, excluding those with selective bone disorders, metastatic cancer, multiple myeloma, kidney dialysis or transplant. Prior VFX diagnosis was based on ICD-9/10-CM diagnosis codes in the 5 years prior to or at BP initiation, excluding fracture codes related to open fracture or spinal cord injury. In the 2 years after BP initiation, new or initial encounter diagnoses of VFX were examined among those without prior VFX diagnoses. Findings were compared by race and ethnicity, overall and within age strata (65-74y, 75-85y). New VFX diagnoses after BP initiation were examined using Cox proportional hazard analyses, reporting hazard ratios (HR) with 95% confidence intervals (CI). Results: Among 50,870 women aged 65-85y (56.5% age <75y) who initiated BP (66.9% White, 16.7% Asian/PI, 11.9% Hispanic, 3.2% Black), 2819 (5.5%) had prior VFX diagnosis. By race and ethnicity, 4.5% of White, 2.3% of Asian/PI, 3.5% of Hispanic, and 4.1% of Black women aged 65-74y had prior VFX diagnosis, increasing to 7.9% of White, 6.6% of Asian/PI, 7.9% of Hispanic, and 6.3% of Black women aged 75-85y. During 2 years follow-up after BP initiation and stratified by age, the incidence of new VFX diagnosis (per 1000 person-years) was 8.9 (7.9-9.9) for White, 3.2 (2.3-4.5) for Asian/PI, 7.1 (5.3-9.5) for Hispanic, and 6.8 (3.8-12.3) for Black women aged 65-74y, and 17.4 (15.9-19.0) for White, 13.0 (10.2-16.6) for Asian/PI, 14.2 (11.2-18.1) for Hispanic, and 6.1 (3.1-12.2) for Black women aged 75-85y. Adjusting for age, prior clinical fracture, and BP initiation year, the risk of new VFX diagnosis among women aged 65-74y (White as reference) was much lower for Asian/PI women (HR 0.40, CI 0.28-0.57) but not Black (HR 0.70, CI 0.38-1.29) and Hispanic (HR 0.80, CI 0.59-1.10) women. For older women aged 75-85y, the risk was much lower for Black women (0.36 (CI 0.18-0.72) but not Asian/PI (0.78, CI 0.60-1.02) and Hispanic (0.83, CI 0.64-1.07) women. Conclusion: Compared to White women, much lower VFX diagnosis among younger but not older Asian/PI women and among older but not younger Black women were seen in the 2 years after BP initiation. While new VFX diagnoses may represent prevalent or incident VFX and underlying fracture risk and continuation of BP may differ by group, these pilot findings support the need for more studies examining ethnic variation in VFX among older women, including differences by age. Presentation: 6/3/2024