National Trends in Lumbar Puncture from 2010 to 2018: A Shift Reversal from the Emergency Department to the Hospital Setting for Radiologists and Advanced Practice Providers

DISCUSSION

Kroll et al¹ demonstrated that between 1991 and 2011, LP procedures on Medicare beneficiaries have increased, with radiology becoming the dominant overall provider. While this previous study depicted a roughly 4-fold increase of the LP procedure share for radiologists during 2 decades, the present study shows smaller differences but a continuation of this trend and changes in procedure shares among physician and nonphysician groups.

Although being already the dominant overall provider at the beginning of the previous decade, interventional and noninterventional radiologists combined had the largest procedure share increase during the past 9 years of all groups. This contrasts with many other areas of image-guided procedures in which “turf wars” continue to emerge among different specialties, often to the disadvantage of radiologists.⁸ Various minimally invasive procedures, originally developed and performed by radiologists, such as coronary angiography, neurointerventional procedures, or noncardiac peripheral vascular interventions, are now mainly performed by other specialists, including cardiologists, neurosurgeons, and vascular surgeons.^9⇓-11

Even though there is a provider specialty shift toward radiologists, the underlying reasons leading to this development are likely not solely attributable to the advantages of image guidance or the growing of radiologists’ expertise. LPs are time-consuming procedures with relatively low reimbursement rates. In 2018, the national average Medicare physician payment for a diagnostic LP performed was $64.30, and for a therapeutic LP, it was $69.55. In contrast, the Medicare payment for reporting a brain MR imaging with and without contrast was $128.60, and for a lumbar spine MR imaging without contrast, it was $96.58. Additionally, to be able to perform image-guided LPs, other resources such as a fluoroscopy/CT system and a radiology technologist are required. A similar development has been shown with paracentesis and thoracentesis procedures, for which radiologists became the main provider during the past decades,¹² in part due to unfavorable economics that are comparable with that of LP procedures. Simultaneously, the demand for productivity and workload has increased for radiologists and clinicians alike,^13⇓⇓-16 contributing to the relatively low-paid/time-consuming procedures, which could further aggravate stress in daily clinical practice, being, instead, referred to other services.

Nevertheless, this trend also offers distinct opportunities for radiologists. While there is no doubt that radiology services are indispensable to the care of patients, concerns about a prestige problem have been raised in the past by various leaders in the field,¹⁷ and there is broad agreement that it is crucial for the future of radiology to have more direct patient contact. This concept can contain different aspects of patient-centered care and, depending on the subspecialty, may include minimally invasive procedures, outpatient care, or better communication with the patient.^18,19 Furthermore, by reinforcing their role in patient care, radiologists can improve their reputation and strengthen relationships with referring providers.²⁰

Another emerging trend demonstrated in this study is the marked increase in procedure shares among APPs. APPs recorded the largest rise in procedure shares among all groups when radiologists and interventional radiologists are considered separately. Likewise, the overall procedure shares of APPs in 2018 are only minimally lower compared with those of neurologists, a previously dominant specialty for LPs. This practice is concurrent with developments described for other procedures such as paracentesis, thoracentesis, fine-needle aspirations and biopsies, and reported nationwide performances of nonvascular invasive procedures by APPs of between approximately 1% and 11%.²¹ Reasons for this change are multifactorial, with the progressing physician shortage certainly playing a major role.²² This trend is likely going to continue, especially with the growing acceptance and comparable procedure outcomes between trained APPs and physicians.^21,23,24

After a peak in 2012, there has been a steady decline in the performance of LP procedures in EDs. During the previous decades, overcrowding in EDs has become a well-known reality,^25,26 and an increasing number of ED visits has likely further aggravated this situation.²⁷ Therefore, the development observed in our study might be a reflection of increased demand for throughput in EDs. This change represents a reversal of earlier decade trends, which showed a marked increase of LP procedures in EDs.¹ A decrease in the length of a hospital stay for many diseases/conditions may contribute to an accelerated transfer from the ED to the inpatient setting and the observed increase of inpatient LPs. Outpatient LPs are predominantly performed in the hospital outpatient department setting, which demonstrated steady growth, a development that led to more LPs being performed in the hospital outpatient department setting from 2016 onward than in the ED. Finally, a decreasing number of LPs were performed in private offices during the past decade; however, this represents a continuation of earlier decade trends.¹

Limitations of this study include, besides its retrospective nature, that Physician/Supplier Procedure Summary Master Files only pertain to the Medicare Part B Fee-for-Service population and our study results are not generalizable because patients with coverage from other federal programs, private health insurance, or those uninsured are not included. Nevertheless, the Physician/Supplier Procedure Summary Master Files are frequently used for this type of study because they are the largest and most reliable data source. Also, due to the increasing share of LPs performed by APPs, the overall percentages for major specialties could be affected if a different number of APPs work under the aegis of supervising specialty groups. However, although LPs performed by APPs are increasing, it is questionable whether they cause significant differences among specialties yet, and they should not account for the observed trends in this study. Further investigations are needed to determine a potential relation between LP procedure shares and the number of APPs working under different specialties.