Background Low back pain (LBP) is a common presentation in primary care and accounts for nearly 100 billion USD in total costs per year in the United States. However, little is known about the burden and recent trends of LBP related hospitalization in the USA.
Objectives To study the ten year trends of LBP hospitalization rates and associated costs from a US national database.
Methods Using the Nationwide Inpatient Sample (NIS), we evaluated trends in LBP hospitalizations between 2001 and 2010. Hospitalizations were categorized as either primary or secondary LBP hospitalizations based on the location of LBP in the discharge diagnoses (ICD-9 code of 724.2). National estimates were calculated using the sampling weights of the NIS. Age- standardized hospitalization rates were determined by dividing the number of hospitalizations by the U.S. population in a given year and using direct standardization. Total hospital charges for hospital stays were adjusted for aggregate inflation rates.
Results The number of primary LBP hospitalizations in the United States decreased from 28,458 in 2001 to 20,615 in 2010, whereas secondary LBP hospitalizations increased from 163,112 to 411,694 over the same period. From 2001 to 2010, age adjusted rates of primary LBP hospitalizations decreased steadily from 10.03 to 6.39 per 100,000 people, respectively (P for trend, <0.001); while age adjusted rates of secondary LBP hospitalizations increased from 57.42 to 126.23 per 100,000 people, respectively (P for trend, <0.001). Use of diagnostic imaging modalities (CT, MRI, Myelogram) decreased steadily during past decade (P for trend, <0.001) both among rural and urban hospitals. Use of spinal canal injection decreased (P for trend, <0.001) but use of physical therapy, spinal fusion surgery and laminectomy increased steadily (P for trend, <0.001, for each of the treatment modalities). In-hospital mortality rate remained stable; ∼1% and hospital length of stay was on average 4.7 days during last decade. Inflation-adjusted total hospital charges associated with LBP hospitalization increased steadily during the past decade (P for trend, <0.001); urban hospitals consistently charged almost two times of rural hospitals during this period (P<0.001).
Conclusions There was a steady decline of hospitalizations with LBP as a primary etiology over the last decade in USA. However, prevalence of LBP as comorbidity increased steadily among US hospitalizations. The economic burden associated with LBP hospitalization has increased over time despite steady state length of hospital stays. Further investigation into the measures needed to decrease hospitalization cost related to LBP is needed.
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Disclosure of Interest : None declared