Discussion
As the most significant change in healthcare in the history of this country continues to evolve, the impact of MACRA, the legislation that repealed the SGR, is not well understood by most providers.6 11 Like their participating clinicians, many healthcare delivery systems are nowhere near prepared to deal with planned changes in documentation, accountability, and reimbursement. A merit incentive payment system will determine provider incentives or penalties based on a composite score predicated on quality, resource consumption, clinical practice improvement efforts, and advancement of clinical information. The legislation calls for the staged replacement of fee for service by APM with the intent to eventually have less than 25% of clinical care paid by a fee for service model by 2025.
What is certain is that the intent of MACRA is optimal quality and increasing cost containment, both of which have for decades been espoused as operating principles of trauma systems. A major component of the MACRA strategy is avoidance of unnecessary expense and use of clinical pathways reflecting best practice that can minimize inappropriate variation in care.12 13 This too has been a well-articulated principle of management of trauma care.
From the perspective of trauma system planning, many of these goals have been embedded in the operating principles of trauma care for decades. The questions that must be addressed regarding delivery of trauma care therefore relate to whether there is enough predictability to enable application of some method of injury-based bundling of care. Because accountable care organizations must be capable and willing to assume significant downside revenue risk to be eligible to share in upside savings, it is essential that, in addition to determining whether trauma care can be bundled, the actual costs of this care in whatever system is applied must be objectively defined. Moreover, regardless of the payment system that will be required to support trauma care into the future, a process of monitoring cost and its association with severity and outcome must be devised. Accordingly, we sought to assess the feasibility of bundling trauma patient care by specific injury patterns, and, by analyzing the variation of resource use within common injury patterns, to determine whether financial risk within these profiles was predictable.
The AIS system of injury14 description has been in use for over 50 years. It was initially devised by engineers to assist in the safe design of highways. The system has been incorporated into the ISS8 and into various mortality prediction models devised over the last four decades. Although the AIS has many shortcomings and has been revised multiple times, it does present a description of injured body regions. The convention of the ISS of using just the highest AIS score from the three most severely injured regions limits the accuracy of the ISS in defining the true extent of injury within a body region. Assessment of almost 6000 patients treated over 2 years clearly shows that the variation of regions alone is far too great to define a predictable pattern or patterns of injury that could be expected to define a reliable range of anticipated cost of care. Any attempt to construct a process for predicting cost of care as part of an alternative payment system will obviously need to adjust for many more variables associated with each injured region and every damaged organ. Moreover, the effect of comorbid conditions will also require consideration. Such a predictive model will probably be based on injury inventory rather than a global assessment of cost of care as stratified by the profile of the highest AIS score of injured body regions. From the perspectives of resource consumption and mortality risk, the wide variation within the vast majority of identified patterns further undermines the predictive accuracy of this concatenated body region injury profile, especially when considering unknown and undiagnosed patient comorbid conditions that may also be present.
So, if our model cannot define adequate similarities between our selected patient groupings, is this analysis unlikely to define strategies for preparation for MACRA? From the perspective of defining common profiles of injury, or specific profiles that may be associated with unique needs, monitoring of the association among incidence, severity, and cost of specific injury patterns will inform planners, providers, and payers as to the expense associated with treatment of the disease of injury. This will be especially valuable for population assessment and for global accountability of trauma system function. Theoretically, the dissemination of best practice protocols should be reflected by a narrowing of the variation of cost for high incidence injury patterns. Similarly, determination of drivers of variation of Ps for specific injury patterns will help define best practice. Comparison of these relationship among states or regions may help define more effective prevention and public education strategies.
This study does have some limitations. The major limitation of this analysis is that it represents the experience of a single institution over 2 years. Using only inpatients for that analysis of severity and cost may exclude significant additional findings associated with the process of care of injured patients who do not require admission. It is well known that the per minute cost of care in the resuscitation room of a designated trauma center is among the highest along the continuum of care, so specific findings associated with these types of injuries are not apparent in this data set. This is especially so when considering the impact of ‘trauma activation’ fees, which have been reported to be as high as $27 000 at some for-profit institutions. Because this has not been validated elsewhere, interpretation of these results may be limited. Nevertheless, the primary message of significant injury variability and limited predictability of cost clearly indicates that additional research focused on these issues will be essential for effective and equitable implementation of the proposed tenets of MACRA.
Additionally, this study only examines one proposed model for developing an APM for trauma. It does not consider other factors such as the mechanism of injury, age, sex, race, or insurance status. Perhaps some combination of these factors coupled with some, or all, of the highest AIS scores would produce a model that could be used as an APM for trauma care.