Same-Day Sinus and Brain CT Imaging in the Medicare Population: Are Practice Patterns Changing in Association with Medicare Policy Initiatives?

Discussion

Although the frequency of same-day sinus and brain CT imaging in the Medicare fee-for-service population is low, it did, in fact, increase in the years leading up to the early stages of implementation of a specific Medicare metric program designed to identify and curb such same-day examinations, supporting the rationale for such an initiative. In the 2 years from metric testing until actual implementation, the frequency of same-day studies plateaued. While we are unable to attribute causation to the OP-14 initiative, our results, nonetheless, suggest that gains are being made in achieving desired testing behavior in accordance with the goals of Medicare. This trend parallels the national stabilization in the use of sinus and brain CT examinations overall (ie, not necessarily on the same day), which began in 2009, suggesting a greater overall awareness of appropriateness in general, which may, in part, be related to concerns about rising costs.

Related to these trends is a new societal emphasis on patient radiation exposure. The effort of professional organizations to reduce radiation doses, such as the Image Wisely campaign,¹¹ as well as public awareness and media attention¹² to the potentially harmful side effects of ionizing radiation, may also be impacting effort to reduce use and, therefore, overall population dose. While our study cannot directly link increased radiation awareness to the slowing of growth in medical imaging, it likely contributed to at least part of the decline in imaging studies.

When identifying potential reasons for the increase of same-day studies up to the rollout of the OP-14 policy initiative of Medicare, the most remarkable contributions to overall growth were those performed in the ED setting. Of note, OP-14 applies specifically to the hospital outpatient setting, but the changes in that setting parallel those in all other settings except for the ED. The reasons for this trend and the ED divergence are multifactorial and can only be partially explained by our work. Despite the stabilization in the overall use of sinus and brain CT imaging since 2009, volume in the ED for CT overall continues to rise.¹³ Our observations for sinus and brain imaging parallel this overall discordant trend, which may, in part, explain the continued increased same-day sinus and brain CT imaging in the ED setting. The national trends reported by Levin et al¹³ used aggregated (ie, no patient-specific information) claims data. Our use of more detailed claims-level data permitted us to examine reported indications for individual examinations, providing additional perspectives. Many simultaneous ED examinations, for example, were ordered in the setting of trauma, infection, or tumor. In such situations, same-day examinations are more appropriate because they include clinical scenarios other than generic headache, such as suspected or known masses involving the paranasal sinuses, face, nasopharynx, or skull base and suspected intracranial extension of infectious processes involving the sinuses.

Nonetheless, almost half of same-day sinus and brain CT scans were not ordered for these 3 specific recognized groups of indications. While our study was not designed to investigate other indications, we can propose several potential explanations.

In our study, we applied exclusion measures for patients with trauma, infection, or tumor on the basis of the ICD codes detailed in the OP-14 criteria, to exclude studies from our analysis that clearly warrant both a sinus and a head CT. Using exclusion criteria based on ICD codes, however, has limitations. While primary ICD codes incorporate the main diagnoses, many additional diagnoses may exist but not be captured through the ICD coding system because coders may focus on only key diagnoses necessary to establish medical necessity in the eyes of a payer. For example, a patient might have a syncopal event with a fall and present to the ED to evaluate presenting symptoms of dizziness. The ED provider may have ordered a sinus CT and brain CT as part of a minor trauma work-up. The traumatic event, however, may not have been captured by the ICD coding, which only included the syncope and/or altered mental status. An additional limitation is that by using administrative claims data, actual sites of service cannot be verified; we thus relied on self-reported sites of service. Because some patients in the ED are subsequently hospitalized, some ED claims could be erroneously reported by using the inpatient hospital setting as the site of service, thus underestimating ED volumes.

Another indication that may account for same-day sinus and brain CT imaging outside the context of trauma, infection, and tumor is headache. Wang and You¹⁴ found that approximately one-quarter of patients without trauma who underwent brain CT in the ED presented with headaches. Because sinusitis is a frequent source of headaches, many same-day studies may have been performed to investigate both the sinuses and brain as causes of headaches, resulting in unnecessary duplicate examinations. Educating ordering physicians that portions of the paranasal sinuses could be covered on routine brain CT examinations or adjusting sinonasal coverage on brain CTs when sinusitis is of clinical concern could help decrease the frequency of duplicate examinations in the work-up of headache. On the other hand, increasing effort to limit the radiation dose to the lens on routine head CT examinations by patient positioning and gantry tilt leads to decreased paranasal sinus coverage, which further underpins the need to tailor the imaging protocols to the clinical and anatomic ROIs.

Independent of the clinical scenarios leading to the ordering of same-day sinus and brain CT examinations, our data clearly demonstrate that the ED is the setting most responsible for the recent increase in simultaneous sinus and brain CT imaging. Multiple studies have already demonstrated an increased use of brain CT in the ED for minor head trauma.^{15⇓⇓–18} Emergency physicians are exposed to growing pressure to address increasing patient loads despite ongoing demands for faster turnaround times and quicker ED and hospital discharges. This likely leads ED physicians to rely more heavily on imaging to achieve quicker diagnoses. While there is no easy solution for this problem, better communication between emergency physicians and radiologists with closer interaction through increasing physical proximity may help both specialties in collaborating to ensure the most appropriate use of imaging for the work-up of patients in the ED.¹⁹ Growing as well are clinical decision-support tools, which may help emergency physicians more effectively leverage finite imaging resources.^20,21

We acknowledge certain limitations to our study. First, the datasets included in our study are from 2004 to 2012 and do not include the recent years 2013 and 2014, which were not available to the authors for analysis at the time of publication. Omitting these data points clearly limits the ability of this study to report on the long-term effects of the OP-14 measure on the performance of same-day brain and sinus CTs. Second, the descriptive methodology of this publication limits the ability to attribute causation to the changes in same-day brain and sinus imaging. Further studies that include more longitudinal data points and incorporate regression-based models may be necessary to prove such causation.