In a northern California population of older women who were treated with oral bisphosphonate drugs, the incidence of atypical femur fracture, a rare complication of treatment, increased with longer duration of bisphosphonate exposure. These findings align with those previously reported in an independent southern California population. INTRODUCTION The age-adjusted incidence of atypical femur fracture (AFF) reported in southern California increased with bisphosphonate (BP) exposure, ranging up to 113 per 100,000 person-years for 8-10-year exposure. This study examines the incidence of AFF in a northern California population. METHODS Women age 45-89 years who initiated oral BP during 2002-2014 in Kaiser Permanente Northern California were followed for AFF outcome, defined by a primarily transverse diaphyseal femur fracture through both cortices, with focal periosteal/endosteal hypertrophy, minimal trauma, and minimal/no comminution. Total BP exposure was determined from dispensed prescriptions. The incidence of AFF, calculated for 2-year BP categories ranging from < 2 to > 10 years, was age-adjusted using the 2000 US Census. RESULTS Among 94,542 women, 107 experienced an AFF during or < 1 year after BP cessation (mean exposure 6.6 ± 3.0 years and total days' supply 5.7 ± 2.8 years at AFF). A strong relationship between AFF incidence and increasing BP exposure was seen, more than doubling for each 2-year category until 8-10 years. Among women with 2- to < 4-year BP, the crude and age-adjusted incidence was 18 and 9 per 100,000 person-years but increased over 2- and 5-fold for women with 4- to < 6- and 6- to < 8-year BP, respectively. For those receiving ≥ 8-year BP, the crude and age-adjusted incidence peaked at 196 and 112 per 100,000 person-years exposure. CONCLUSION Incidence of AFF increases markedly after 4-6 years of BP. These trends align with southern California and confirm a strong BP duration-related risk of this rare but serious event.

中文翻译：

---

女性非典型股骨骨折的发生率随着双膦酸盐暴露时间的延长而增加。


在加利福尼亚州北部接受口服双膦酸盐药物治疗的老年妇女中，非典型股骨骨折（一种罕见的治疗并发症）的发生率随着双膦酸盐暴露时间的延长而增加。这些发现与之前在南加州独立人群中报告的结果一致。引言 南加州报道的非典型股骨骨折 (AFF) 的年龄调整发病率随着双磷酸盐 (BP) 暴露的增加而增加，暴露 8-10 年的范围高达每 100,000 人年 113 例。本研究调查了北加州人群中 AFF 的发病率。方法 对 2002 年至 2014 年在北加州 Kaiser Permanente 开始口服 BP 的 45-89 岁女性进行 AFF 结果随访，其定义为穿过双侧皮质的原发性股骨干横向骨折，伴有局灶性骨膜/骨内膜肥厚、创伤最小、损伤最小。 /无粉碎。总血压暴露是根据处方确定的。 AFF 的发病率按 2 年 BP 类别计算，范围为 < 2 至 > 10 年，并根据 2000 年美国人口普查进行了年龄调整。结果 在 94,542 名女性中，107 名在 BP 停止期间或 < 后 1 年经历了 AFF（AFF 平均暴露时间 6.6 ± 3.0 年，总供应天数 5.7 ± 2.8 年）。 AFF 发病率与 BP 暴露增加之间存在密切关系，每 2 年类别增加一倍以上，直到 8-10 年。在 2-< 4 年 BP 的女性中，粗略和年龄调整后的发病率分别为每 10 万人年 18 和 9 例，但对于 4-至 < 6-和 6 的女性，发病率增加了 2 至 5 倍以上- 分别为< 8 年BP。对于接受 ≥ 8 年 BP 的患者，粗略发病率和年龄调整发病率分别达到峰值，分别为每 10 万人年暴露 196 例和 112 例。 结论 BP 4-6 年后，AFF 的发生率显着增加。这些趋势与南加州一致，并证实了这一罕见但严重事件与血压持续时间相关的强烈风险。