When was the last time you have questioned a patient due to the non-anatomical features related to their work-related injury? When was the last time you utilized Waddell signs to screen for malingering? I want to propose the argument that, in the light of recent developments in our understanding of pain neurophysiology, we should be very reserved in questioning our patient’s complaints. In addition, I believe it is time that we drop the Waddell signs in the screening for potential malingering/secondary gain due to lack of validity in the face of research on central sensitization.
The Diagnostic and Statistical Manual of Mental Disorders, 4th edition has defined malingering as, “the intentional production of false or grossly exaggerated physical or psychologic symptoms motivated by external incentives, such as avoiding military duty, avoiding work, obtaining financial compensation, evading criminal prosecution, or obtaining drugs.” Incentives, which are motivation for malingering, are known as secondary gains.
What are the Waddell Signs?
In 1987, a physician by the name of Gordon Waddell published a paper entitled, “A New Clinical Model for the Treatment of Low-Back Pain”. This paper was well-received and won the 1987 Volvo Award in Clinical Sciences. The paper was revolutionary and provided a new theoretical framework for medical management of low back pain (due to Waddell’s increasing concern about medical mismanagement and patient disability). In this paper, Waddell proposed the notion that the biopsychosocial concept can be used as an operational model that explains many of our patient’s clinical presentations. He proposed that bed rest is harmful, and that there is no evidence to support that movement and activity is harmful. He understood that management of this condition must change . Unfortunately, this pivotal piece is lesser known for some of the concepts/ideas which are relevant even in today’s debates, and instead for a list of signs which he categorized as identifying magnified or inappropriate illness behavior.
Below is a copy of this chart:
|Physical disease/normal illness behavior||Magnified or inappropriate illness behavior|
This chart, known in the paper as Table 7, is described in very short detail on page 638. He recognizes that with the current understanding of low back pain, the responses in the right hand column do not make sense. But to his credit, this is not his fault. Melzack’s proposal of the neuromatrix was still more than a decade away. But despite the lack of Melzack’s model, he discusses the biopsychosocial model and states, “the interaction between physical and psychologic factors determine the outcome of treatment. Work loss and return to work are determined more by social fators than physical disease. All these analysis confirm that the biopsychosocial concept of illness can be used as an operational clinical model which explains many of the observations on the natural history of low back pain and disability”. This quote is quite ahead of its time and I would like to go on a limb to propose that Waddell pulled a “Nostradamus” and saw the future of medicine. There were some concepts which showed a biomedical mindset such as, “we must develop methods of localizing the exact source of pain…” but overall he was quite revolutionary.
Waddell Signs and Central Sensitization
I have written a couple of times on the Mechanism-Based Classification of Pain. When looking at the right hand column in Table 7 (above), one cannot ignore the extreme similarities between the proposed signs and symptoms and Central Sensitization. Below is a review of the diagnostic criteria for central sensitization:
- Pain is disproportionate to the nature or extent of injury/pathology
- Disproportionate, non-mechanical, unpredictable pattern of pain provocation in response to aggravating/easing factors
- Strong association with maladaptive psychological factors
- Diffuse/non-anatomic areas of pain/tenderness to palpation
So with our understanding of Central Sensitization, do you suspect the Waddell signs tell us a malingerer OR someone with a sensitized nervous system? Can these tests be dumped from our infamous bag of tricks? I think so….
Waddell G. A new clinical model for the treatment of low-back pain. Spine 1987; 12: 632-44.
Fishbain DA, Cutler RB, et al. Is there a relationship between nonorganic physical findings (Waddell Signs) and Secondary Gain/Malingering? Clin J Pain 2004; 20: 399-408.