Considering the human toll and economic impact of Whiplash-Associated Disorders (WAD), relatively little is known about this common problem. Studies of neck injury in animal acceleration/deceleration models clearly document one end of a spectrum of tissue damage. Whether lesser trauma in humans can cause enough injury to explain the symptoms seen in WAD cannot, however, be deduced. Although considerable work has been done on WAD, much of it is flawed, uninterpretable or inadequate to form rational clinical or health-care policy. Therefore, fundamental questions remain regarding the pathophysiology, diagnosis, treatment, clinical course and prevention of this disorder. Based on a critical assessment of the published evidence, the Task Force has made a number of recommendations to fill what we perceive as critical gaps in knowledge. Central to these efforts are: 1) a proposed terminology that, coupled with measures of severity, will make future studies comparable and 2) attention to rigorous study design and execution in any new studies.
Future studies would benefit greatly from a standardized description of patients, their sources, physical findings and symptoms of prognostic significance. Standardizing the assessment would ensure that critical baseline information is collected and that studies done in different locations can be compared to one another. Improved precision and standardization of findings would permit the evaluation of the clinical value of conventional X rays and newer but considerably more expensive imaging techniques that display soft tissues in previously unimaginable detail. These latter techniques such as MRI may, in fact, ultimately provide an understanding of the pathoanatomy of WAD. However, in clinical practice, MRI may provide more sensitivity and information than we can interpret, unless studies are done with sufficient numbers of carefully characterized subjects spanning the spectrum of WAD. These tests, as well as electrophysiologic or neuropsychologic studies in WAD, must be evaluated in terms of their clinical value in improving both prognostication and outcomes. With better clinical correlation, in this era of increasing technologic capacity, public expectations and diminishing resources, the cost-effectiveness of these tests must also be evaluated. Paradoxically, new imaging techniques could also restore the history and physical examination to a central role in the initial evaluation of WAD patients and, in the absence of anatomical information, make the history and physical examination the gold standard for the evaluation of other diagnostic technology.
Improved clinical characterization of WAD would also contribute to true population-based studies of the spectrum of disease and its clinical course. This too, would allow comparisons in different settings, especially different disability claims systems, and help to understand the clinical and social determinants of prolonged symptomatology, disability and health resource utilization.
The Task Force was disappointed, despite an exhaustive literature search, by the studies evaluating the common therapeutic interventions for WAD. These studies as a genre are flawed; few met even minimum methodologic standards for scientific rigor. Even in the studies that were well done, small sample sizes and the use of multiple therapeutic interventions in the same subjects made it difficult to deduce the benefits of individual treatments. The lack of crisp endpoints using standardized, valid and reliable measures, particularly patient-centered ones, made it impossible to pool results or to do secondary analyses of effect sizes or of their clinical importance. The imprecise categorization of patients into prognostic strata and the confounding effect of different disability laws made generalizations impossible.
The philosophy of the Task Force in evaluating treatments, was one of prudence in the absence of evidence. We required that any therapeutic intervention should do more good than harm and that health care should not medicalize a condition or reinforce disability behavior. Some therapeutic interventions such as analgesics, antiinflammatory agents and antispasmodics have not been evaluated specifically for WAD; their value for other musculoskeletal injuries might be generalized to WAD. The remaining group included essentially harmless, but either ineffective or marginally effective interventions such as soft collars, special pillows, prescribed exercises, postural attention and traction. Where there was an effect it was small and of short duration. The other category consisted of interventions that were expensive because they were labor intensive or done by professionals and were either unproven or marginally beneficial. These included manipulation, mobilization, spray and stretch, steroid injections and a host of physical approaches to administer heat or cold topically or to the deeper soft tissues.
With a planned research agenda we should have the resources to remedy the shortfalls in our knowledge of WAD.
There are several options for conducting research in this area depending on the research question, context and feasibility. A variety of alternate designs may be used, for example, historical or prospective cohort studies, case-control studies and case-cohort studies. The randomized controlled trial is of course the preferred design for evaluating interventions.
We have divided this agenda into two categories: a) problems of high priority requiring immediate attention and b) problems of importance to be undertaken in the longer term.