title: Trends in lumbar puncture over 2 decades: a dramatic shift to radiology.
abstract: OBJECTIVE
  The purpose of this study is to evaluate national trends in lumbar puncture (LP) procedures and the relative roles of specialty groups providing this service.
  
  
  METHODS
  Aggregated claims data for LPs were extracted from Medicare Physician Supplier Procedure Summary master files annually from 1991 through 2011. LP procedure volumes by specialty group and place of service were studied.
  
  
  RESULTS
  Between 1991 and 2011, the overall numbers of LP procedures increased, with a slight increase in diagnostic LP procedures (90,460 vs 90,785) and a marked increase in therapeutic LP procedures (2868 vs 6461) in Medicare fee-for-service beneficiaries. Although radiologists performed 11.3% (n = 10,533) of all LP procedures in 1991, they performed 46.6% (n = 45,338) in 2011. For diagnostic LPs, radiology (11.4% [n = 10,272] in 1991 and 48.0% [n = 43,601] in 2011) now exceeds emergency medicine, neurosciences, and all others as the dominant provider group. For therapeutic LP procedures, radiology now performs the second greatest number of LP procedures (9.0% [n = 261] in 1991 and 26.9% [n = 1737] in 2011). Although volumes remain small (< 10% of all procedures), midlevel practitioners have experienced over 100-fold growth for most services. The inpatient hospital setting remains the dominant site of service (71,385 in 1991 vs 44,817 in 2011: -37%), followed by procedures performed in the emergency department (297 in 1991 vs 26,117 in 2011: 8794%).
  
  
  CONCLUSIONS
  Over the last 2 decades, LP procedures on Medicare beneficiaries have increased, with radiology now the dominant overall provider. Although this trend may have relatively negative financial implications for radiology practices in current fee-for-service payment models, it has the potential to cement radiology's more central position through direct involvement in patient care in emerging accountable care organizations.
authors.affiliation: 1 Department of Radiology, Neuroradiology Division, University of Virginia, PO Box 800170, Charlottesville, VA 22908-0170.
authors.forename: Hannes
authors.initials: H
authors.lastname: Kroll
authors.forename: Richard
authors.initials: R
authors.lastname: Duszak
authors.forename: Eugene
authors.initials: E
authors.lastname: Nsiah
authors.forename: Danny R
authors.initials: DR
authors.lastname: Hughes
authors.forename: Suna
authors.initials: S
authors.lastname: Sumer
authors.forename: Max
authors.initials: M
authors.lastname: Wintermark
mesh_terms: D006801:Humans; D006278:Medicare / Q000706:statistics & numerical data* / Q000639:trends*; D011871:Radiology / Q000706:statistics & numerical data* / Q000639:trends*; D013129:Spinal Puncture / Q000706:statistics & numerical data* / Q000639:trends*; D014481:United States; D014600:Utilization Review
keywords: health care; lumbar puncture; medical specialty; radiology