The Case

A 24-year-old female enters the emergency department after experiencing a brief loss of consciousness after being hit while playing ice hockey. She feels fine and on evaluation has no complaints of any neurological symptoms, vomiting, or other injury. Her Glasgow Coma Scale score is 15; there is nothing to suggest an open, depressed, or basal skull fracture; and she has no amnesia.

Despite the lack of indication for a computed tomography (CT) scan according to the Canadian CT Head Rule (CCHR), she insists on getting a scan “just to be safe.” You’d like to reassure her in an effort to decrease the risks associated with unnecessary testing and to control costs.

Background

The CT scan has become one of the most important diagnostic tests used in the emergency department. It facilitates the rapid identification of several life-threatening conditions. However, there is evidence that it can be overutilized. One specific problem is the overuse of head CTs. A retrospective study demonstrated that more than one-third of head CTs were not indicated based on the CCHR.1

One way to decrease unnecessary head CTs is to use clinical decision instruments like the CCHR or the NEXUS Criteria. Despite the validation of these clinical decision tools, adaptation by physicians and acceptance by patients can meet resistance. Many factors influence overtesting, including working in a zero-miss culture. Concern for patient satisfaction scores also can influence decisions to order head CTs that are not clinically indicated.

A new study by Iyengar et al looked at ED patients given a hypothetical low-risk head injury case and assessed the impact a financial incentive as well as varying levels of risk and benefit had on their preference for having a CT scan.2

Clinical Question

Can a patient’s preference for unnecessary head CT be influenced with financial incentives in conjunction with potential risk and benefit education?

Reference: Iyengar R, Winkels JL, Smith CM, et al. The effect of financial incentives on patient decisions to undergo low-value head computed tomography scans. Acad Emerg Med. 2019;26(10):1117-1124.

• Population: Adult patients presenting to an academic emergency department.
  • Exclusions: Patients with chest pain, head trauma, altered mental status, or contact precautions; patients treated in the resuscitation bays.
• Intervention and Comparison: A hypothetical low-risk head trauma scenario was presented. The clinical scenario suggested against imaging according to the CCHR. Three aspects of the scenario were randomized:
  • Benefit: Presented as either 1 percent or 0.1 percent.
  • Risk: Presented as either 1 percent or 0.1 percent.
  • Incentive: Patients were offered either no money or a $100 financial incentive to forgo the unnecessary CT. Multiple formats were used to present the potential risks and benefits, include percentages (0.1 percent), ratios (1 in 1,000), and visual depictions.
• Outcome: 
  • Primary Outcome: Percentage of patients who would choose to get a CT scan.
  • Secondary Outcome: Multiple regression analyses to control for potential confounders.
  • Authors’ Conclusions

“Providing financial incentives to forego testing significantly decreased patient preference for testing, even when accounting for test benefit and risk. This work is preliminary, hypothetical, and requires confirmation in larger patient cohorts facing these actual decisions.”