Pathologic fractures from bone metastases can significantly affect quality-of-life, although it is unclear which patients may be at high risk of this outcome. We aim to determine risk factors for pathologic fracture among patients admitted with bone metastases and to evaluate the association of pathologic fracture with clinical and economic outcomes.
The Healthcare Cost and Utilization Project National Inpatient Sample was queried for all patients hospitalized with bone metastases in 2016. Baseline differences between patients with and without pathologic fractures were assessed by χ2 and analysis of variance testing. Multivariable logistic regression was used to identify factors associated with fractures.
In 2016, 272,275 hospital admissions were associated with a diagnosis of bone metastases, of which 11,960 (4.4%) had a primary diagnosis of pathologic fracture. Patients with pathologic fractures had a longer length-of-hospital-stay (mean 7.5 vs. 6.4 d; P<0.001) and higher cost-of-hospital-stay (mean $23,611 vs. $15,942; P<0.001) compared to patients without pathologic fractures. Primary cancers associated with increased likelihood of pathologic fracture included liver and intrahepatic bile duct (odds ratio [OR] 2.34; 95% confidence interval [CI], 1.65-3.32), multiple myeloma (OR 1.94; 95% CI, 1.31-2.86), and kidney and renal pelvis cancer (OR 1.89; 95% CI, 1.50-2.37).
Nearly 5% of hospitalizations with bone metastases presented with a concomitant pathologic fracture, which was associated with longer inpatient stay and higher cost. Patients with hepatobiliary, renal cell carcinoma, or multiple myeloma, had a higher likelihood of pathologic fracture. These groups may benefit from increased outpatient monitoring, prophylactic stabilization, or early irradiation.