Department of Endocrinology, CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium.
Data Centre, Inst. J. Bordet, Université Libre de Bruxelles, Brussels, Belgium.
Arch Osteoporos. 2020 Apr 22;15(1):61. doi: 10.1007/s11657-020-00739-y.
We assessed the rate of non-reported fractures in the FRISBEE cohort. Over a median follow-up period of 9.2 years, we registered 992 fractures. The global percentage of non-reported fractures was 21.3%. Underreporting of fracture event might influence any model of fracture risk prediction.
Most fracture cohort studies rely on participant self-report of fracture event. This approach may lead to fracture underreporting. The purpose of the study was to assess the rate of non-reported fractures in a well-characterized population-based cohort of 3560 postmenopausal women, aged 60-85 years, included in the Fracture Risk Brussels Epidemiological Enquiry (FRISBEE) study.
Incident low-traumatic or non-traumatic fractures were registered annually during phone calls. In 2018, we reviewed the medical files of 67.9% of our study participants and identified non-reported fractures ("false negatives fractures (FN)"). We also evaluated whether the rate of FN was influenced by baseline patients' characteristics and fracture risk factors. Generalized estimating equation (GEE) was used to calculate odds ratio (OR) and 95% CI.
Over a median follow-up period of 9.2 years, we registered 992 fractures (781 by self-report, confirmed by a radiological report and 211 unreported). The global false negative rate for all fractures was 21.3%, including 22% for MOFs (major osteoporotic fractures), 13.1% for other major fractures, and 25.8% for minor fractures. The rate of non-reported fractures varied by fracture site: for MOFs, it was 2.7% (n = 2/73) at the hip, 5.3% at the proximal humerus (n = 5/94), 7.1% at the wrist (n = 11/154), and 46.5% at the spine (n = 100/215). For "other major" fractures, the highest rate of false negatives fractures was found at the pelvic bone (21%, n = 13/62), followed by the elbow (17.9%, n = 5/28), long bones (10.5%, n = 2/19), ankle (6.2%, n = 4/65), and knee (5.9%, n = 1/17). Older subjects (OR 1.7; 95% CI, 1.2-2.4; P = 0.003), subjects with early non-substituted menopause (OR 1.8; 95% CI, 1.0-3.3; P = 0.04), with a lower education level (OR 1.5; 95%CI, 1.1-2.2; P = 0.01), and those under drug therapy for osteoporosis (OR 1.5; 95% CI, 1.0-2.2; P = 0.05) were associated with a higher rate of FN.
In conclusion, underreporting of a substantial proportion of fracture events will influence any model of fracture risk prediction and induce bias when estimating the associations between candidate risk factors and incident fractures.
FRISBEE 队列研究。在中位随访 9.2 年期间，我们登记了 992 例骨折。全球未报告骨折的百分比为 21.3%。骨折事件的漏报可能会影响任何骨折风险预测模型。
大多数骨折队列研究依赖于参与者对骨折事件的自我报告。这种方法可能导致骨折漏报。本研究的目的是评估在一个由 3560 名年龄在 60-85 岁的绝经后妇女组成的特征明确的基于人群的队列（FRISBEE 研究）中未报告骨折的发生率。
每年通过电话登记低创伤性或非创伤性骨折。2018 年，我们查阅了 67.9%的研究参与者的医疗记录，并确定了未报告的骨折（“假阴性骨折（FN）”）。我们还评估了 FN 率是否受到基线患者特征和骨折危险因素的影响。使用广义估计方程（GEE）计算比值比（OR）和 95%置信区间（CI）。
在中位随访 9.2 年期间，我们登记了 992 例骨折（781 例由自我报告证实，有放射学报告，211 例未报告）。所有骨折的总体假阴性率为 21.3%，其中 MOFs（主要骨质疏松性骨折）为 22%，其他主要骨折为 13.1%，次要骨折为 25.8%。未报告骨折的发生率因骨折部位而异：MOFs 在髋部为 2.7%（n=2/73），在肱骨近端为 5.3%（n=5/94），在腕部为 7.1%（n=11/154），在脊柱为 46.5%（n=100/215）。对于“其他主要”骨折，假阴性骨折发生率最高的部位是骨盆（21%，n=13/62），其次是肘部（17.9%，n=5/28），长骨（10.5%，n=2/19），踝部（6.2%，n=4/65）和膝部（5.9%，n=1/17）。年龄较大的受试者（OR 1.7；95%CI，1.2-2.4；P=0.003）、早期非替代绝经的受试者（OR 1.8；95%CI，1.0-3.3；P=0.04）、教育程度较低的受试者（OR 1.5；95%CI，1.1-2.2；P=0.01）和接受骨质疏松药物治疗的受试者（OR 1.5；95%CI，1.0-2.2；P=0.05）与 FN 发生率较高相关。
总之，大量骨折事件的漏报将影响任何骨折风险预测模型，并在估计候选风险因素与新发骨折之间的关联时引起偏倚。
