OUTCOMES

Outcomes may be viewed differently from the perspective of the patient, provider, payer, and society. The standard outcome parameters are outlined in Table 1. Although survival (live/die) seems straightforward, the endpoint in time may vary considerably, including in hospital, 30 days, 6 months, 1 year, and time to death. These variations project imprecision into many of the existing severity scoring and mortality prediction models.

Table 1 Outcome Parameters in Medicine

Survival (mortality) Complications (morbidity) Length of stay Cost Quality of life Patient satisfaction Compliance with guidelines

The use of morbidity as an outcome requires distinguishing between a complication and a pre-existing condition (i.e., a comorbidity) and providing a precise definition of a complication. A wound infection requires a precise diagnosis using the NISS classification; however, many of the infections are discovered and treated as outpatients and are never recognized by registries. Distinguishing between pre-existing renal or pulmonary disease and subsequent renal or pulmonary dysfunction after trauma can be challenging.

Hospital length of stay is a gross parameter of quality or outcome because of the variety of practices in institutions relative to the use of intensive care unit, step-down, floor, and outpatient care. The effect of early discharge is widely unknown relative to the effect on the patient’s family, visiting nurses, physician’s offices, and unanticipated hospital readmissions.

As with all outcome parameters, the cost of trauma care can be in the eye of the beholder. The payer is likely to know his/her cost with some precision, which usually reflects what he/she paid plus administrative costs. The patient usually perceives the cost as out-of-pocket expenses plus lost wages. However, the cost to the providers (i.e., emergency medical services, physician, and hospital) has many confounding variables, and is much less precise. The cost to society is even more abstract and studies have revealed substantial variation in estimates.

Quality of life has been recognized by researchers as desired outcome measures. The Functional Independence Measure (FIM), Glasgow Outcome Scale (GOS), Functional Capacity Index (FCI), Quality of Well-Being Scale, Sickness Impact Profile (SIP), and the SF-36 Survey are among the most popular in trauma-related outcome studies. Some are labor intensive and become impractical except for focused studies.

Many commercially available survey tools are religiously utilized by hospital and system administrators as measures of patient satisfaction. Goals are frequently set to meet target scores, suggesting either improvement or decline in outcome.

Finally, measuring compliance with evidence-based guidelines can provide a measurement of outcomes. Studies of compliance with Advanced Trauma Live Support (ATLS) guidelines, as well as head injury guidelines, have provided several outcome studies. Using guideline compliance as an outcome itself assumes that the desired outcome is compliance, inferring improvement in other standard patient outcomes based on the evidence on which the guidelines were developed. Therefore, caution is required in interpreting this outcome parameter.

EVIDENCE-BASED MEDICINE

The discipline of evidence-based medicine has emerged over the past decade to allow investigators to quantify the power of scientific studies based on the certainty of the scientific methods employed. Although simplistic, a classification system has been well received by the medical community that allows dialog among investigators (Table 2). Fortunately, the trend of dominance of class III data in the world of trauma outcomes is slowly giving way to significant class II and class I outcome studies in trauma and critical care.

Table 2 Evidence-Based Classification of Outcome Studies

Evidence	Description
Class I	Prospective, randomized, controlled trials—the gold standard of clinical trials. However, some may be poorly designed, lack sufficient patient numbers, or suffer from other methodological inadequacies.
Class II	Clinical studies in which the data were collected prospectively; retrospective analyses based on clearly reliable data. Types of study so classified include observational studies, cohort studies, prevalence studies, and case–control studies.
Class III	Most studies based on retrospectively collected data. Evidence used in this class indicates clinical series, databases, registries, case reviews, case reports, and expert opinion.
Technology assessment	The assessment of technology, such as devices for monitoring intracranial pressure, does not lend itself to classification in the format above. Thus, for technology assessment, devices were evaluated in terms of accuracy, reliability, therapeutic potential, and cost effectiveness.

In general, class I and class II studies provide the fuel for the strongest evidence-based guidelines on which to base the processes of trauma care (Table 3). The value of class III studies is to point the researcher toward an area of need and to help formulate the appropriate null hypothesis for a higher-power study. However, there are many clinical questions that have prohibitive barriers that prevent class I and class II studies, thereby augmenting the value of class III evidence.

Table 3 Trauma-Related Evidence-Based Guidelines

1. Resuscitation end points 2. Emergency department thoracotomy 3. Management of mild traumatic brain injury 4. Severe closed head injury 5. Identifying cervical spine injuries after trauma 6. Screening of blunt cardiac injury 7. Diagnosis and management of blunt aortic injury 8. Prophylactic antibiotic use for tube thoracostomy 9. Evaluation of blunt abdominal trauma 10. Nonoperative management of blunt injury to liver and spleen 11. Prophylactic antibiotic use in penetrating abdominal trauma 12. Penetrating intraperitoneal colon injuries 13. Pelvic fracture 14. Genitourinary injury 15. Optimal timing of long bone fracture stabilization in polytrauma patients 16. Prophylactic antibiotic use in open fractures 17. Management of penetrating trauma to lower extremity 18. Venous thromboembolism in trauma patients 19. Ventilator management of patients with respiratory failure 20. Nosocomial pneumonia 21. Weaning and extubation 22. Agitation and sedation 23. Alcohol withdrawal prophylaxis 24. Pain management 25. Stress ulcer prophylaxis 26. Infection control of invasive lines 27. Nutritional support of trauma patient 28. Albumin transfusion 29. Hyperglycemia 30. Geriatric trauma 31. Violence prevention programs

PERFORMANCE IMPROVEMENT AND PATIENT SAFETY

For over two decades, performance improvement (previously called quality assurance) has been a centerpiece of trauma care as promulgated by the American College of Surgeons Committee on Trauma. Recently, as a result of studies by the Institute of Medicine and the response to those studies by the Joint Commission on Accreditation of Health Care Organizations, patient safety has been added to the equation. Most health care organizations are under a mandate for demonstration of performance improvement and patient safety (PIPS) initiatives.

The Surgical Care Improvement Project (SCIP) is a national initiative to improve outcomes for patients having surgery. This project represents a coalition of 10 organizations, including the American College of Surgeons, Agency for Healthcare Research and Quality, Centers for Medicare and Medicaid Services, and Joint Commission on Accreditation of Healthcare Organizations. Although some of the initiatives are not specific to trauma care, many relate to critical care and general care of any patient, including those with injury (Table 4). Most of these initiatives are centered on evidence-based guidelines reflective of class I or II outcome studies. Therefore, it is important to understand the very strong link between trauma/critical care–related PIPS and outcome studies.

Table 4 Surgical Care Improvement Project: Process and Outcome Measures

Infection

Prophylactic antibiotic received within 1 hour prior to surgical incision Prophylactic antibiotic selection for surgical patients Prophylactic antibiotics discontinued within 24 hours after surgery end time (48 hours for cardiac patients) Postoperative wound infection diagnosed during index hospitalization (OUTCOME) Surgery patients with appropriate hair removal Colorectal surgery patients with immediate postoperative normothermia

Cardiac Venous Thromboembolism Respiratory Global

NATIONAL TRAUMA DATA BANK

In 1989, the Regents of the American College of Surgeons established the National Trauma Data Bank (NTDB) subcommittee under the aegis of the American College of Surgeons Committee of Trauma. The goal of this initiative was to develop a database that would serve as a national repository of data on trauma center care in the United States. After completing its preliminary work, including establishing the standard data set of 93 elements, the NTDB initiated a first call for data in 1997. It continues to do so annually, requesting data from the previous year. As of 2005, the NTDB has accrued over 1.4 million records from 405 U.S. trauma centers in 43 states, territories, and the District of Columbia, making it the largest aggregate of trauma data ever assembled. Table 5 outlines research studies that were at least in part based on the NTDB.

Table 5 National Trauma Data Bank–Related Research

Epidemiology

George RL, et al: The association between gender and mortality among trauma patients as modified by age. J Trauma, 2003. Hawkins A, et al: The impact of combined trauma and burns on patient mortality. J Trauma, 2005. Ikossi DG, et al: Profile of mothers at risk: an analysis of injury and pregnancy loss in 1,195 trauma patients. J Am Coll Surg, 2005. Kon AA, et al: The association of race and ethnicity with rates of drug and alcohol testing among US trauma patients. Health Policy, 2004. Marcin JP, et al: Evaluation of race and ethnicity on alcohol and drug testing of adolescents admitted with trauma. Acad Emerg Med, 2003. McGwin G Jr, et al: Pre-existing conditions and mortality in older trauma patients. J Trauma, 2004. Minei JP, et al: Gender differences in survival may be due to a lower risk of complications in females: an analysis of the National Trauma Data Bank. Presented (poster) at annual meeting of American Association for the Surgery of Trauma, Maui, HI, September 2004. Santaniello JM, et al: Ten year experience of burn, trauma, and combined burn/trauma injuries comparing outcomes. J Trauma, 2004. Steljes TP, et al: Epidemiology of suicide and the impact on Western trauma centers. J Trauma, 2005.

Prevention System Scoring Prehospital ShafiS, et al: Prehospital endotracheal intubation and positive pressure ventilation is associated with hypotension and decreased survival in hypovolemic trauma patients: an analysis of the National Trauma Data Bank. J Trauma, 2005. Resuscitation Operating Room Critical Care Friese RS, et al: Pulmonary artery catheter is associated with reduced mortality in severely injured patients: a National Trauma Data Bank analysis of 53,312 patients. J Trauma, 2004.

Although the sheer size of the NTDB makes it an attractive resource for trauma-related research and benchmarking, it has several significant limitations. The NTDB represents a convenience sample of trauma care provided by the participating hospitals, which are predominately trauma centers. Accordingly, it can not be used as a population-based assessment of U.S. trauma care.

The NTDB contains data originally collected using many different trauma registry programs. Because of the variability of the data definitions contained in the registry programs, there is significant data variability within the data set of the NTDB itself. In order to limit this variability, the data files are scanned to ensure that they are within valid ranges prior to entry. Presently, the NTDB Subcommittee with assistance from the U.S. Health Resources and Service Administration is engaged in a major effort to standardize the NTDB’s data set for eventual distribution to the participating hospitals.

The NTDB’s nonsystematic sampling also lends itself to a selection bias. This bias makes benchmarking problematic, as not all hospitals or trauma centers participate and certain injuries (e.g., hip fractures) are not uniformly reported. Furthermore, because of the voluntary and nonuniform nature of reporting, the NTDB participating hospitals can provide varying amounts of data within the data set. As many hospitals fail to report certain information such as complications or comorbidities, comparative analysis in these areas is impossible.

NATIONAL SURGICAL QUALITY IMPROVEMENT PROGRAM

The National Surgical Quality Improvement Program (NSQIP) was developed by the Veterans Administration in response to a congressional mandate to demonstrate optimal outcomes in the VA Hospitals. The program was developed by surgeons for surgeons and represents the first attempt at measuring surgical outcomes from a clinical rather than an administrative database.

This program is sponsored by the American College of Surgeons and is currently being promulgated to nonmilitary health care organizations. The Committee on Trauma of the American College of Surgeons is working with NSQIP to provide a trauma-related outcome module. This will provide a much more robust tracking of morbidities and will allow validation of the definitions of complications.

SUMMARY AND FUTURE DIRECTION

The ability to demonstrate high-quality outcomes for all health care efforts will be essential for surgeons, including those caring for the injured. The quality of outcome data continues to improve, especially in the areas of the critical-care phase of trauma. The National Trauma Data Bank and the National Surgical Quality Improvement Program can provide platforms to benchmarking. There is a need for improvement in the precision of definitions of outcome parameters, especially in the area of complications. The electronic health record of the future will include a repository, clinical decision support, and an integrated concurrent data management system that will allow for much better local outcome assessment. National efforts to improve funding for trauma outcome studies will be necessary to improve the quality of outcome studies, especially in the prehospital, resuscitation, and operative phases of trauma care.