Factors associated with recovery expectations following vehicle collision: A population-based study.
From: J Rehabil Med. 2010 Jan;42(1):66-73
Whiplash associated disorders are a common problem, estimated at 300–600 cases per 100,000 population per year in North America and western Europe. They are costly to insurance/medical systems, and may result in long-term disability in the injured person, including increased risk of future neck pain and other health complaints. Clinically, there is uncertainty about how to manage these injuries, and the scale and complexity of the whiplash dilemma makes whiplash injuries an important public health concern. Although many different treatment modalities have been studied, these treatment effects in whiplash associated disorders are modest at best, and frequently short-lived. This suggests that other types of interventions may be required to reduce disability and improve outcomes. As such, researchers and clinicians should focus attention on factors that have demonstrated independent associations with patient recovery.
One already demonstrated and clinically meaningful approach is to focus on patients’ expectations about their own recovery. Studies have consistently shown that, for a wide variety of medical conditions, positive expectations for recovery are positively associated with better clinical outcomes, from increased success of rehabilitation and to reduced levels of post-operative pain. In addition, 2 recent studies have identified recovery expectations as important in whiplash associated disorders recovery. In fact, in a Canadian study, those with whiplash associated disorders having positive expectations recovered more than 3 times faster than those who expected never to get better. A Swedish study found a dose-response relationship between recovery expectations and disability 6 months after the crash. After controlling for severity of physical and mental symptoms, individuals who expected they would not make a full recovery were over 4 times more likely to have a high disability; those who self-rated as having “intermediate” recovery expectations were over two times more likely to have high disability. Both groups were compared to those stating they were very likely to make a full recovery. Given the substantial effect size and independent relationship demonstrated by recovery expectation on recovery in both whiplash associated disorders population studies, assessing patients’ expectations early in the injury experience appears useful, particularly in identifying those who have the greatest concerns regarding their recovery, thus helping reduce the burden of whiplash associated disorders in this vulnerable group. Moreover, such findings lead to the prospect that modifying a persons’ expectation for whiplash associated disorders recovery will speed their actual recovery and thus decrease the burden of impairment and disability.
However, very little is known about how individuals formulate health expectations. Understanding how they are formed is a crucial step in understanding how they can be modified. Janzen et al. have recently offered a conceptual model describing how health expectations are formulated, and have performed some validation work with expectations in Alzheimer’s disease. This model suggests that expectations are formulated through a number of interacting processes, including prior knowledge, cognitive processing, and outcome evaluation. The model acknowledges that expectations are socially and culturally contingent, governed by one’s understanding of the world, and are contextually specific; principles that are in keeping with the biopsychosocial model of health. While the model appears to provide a basis for study of expectation for soft tissue injuries, there has not been any validation of it with a whiplash associated disorders population. Knowledge of how expectations are formulated in a whiplash associated disorders population would prove useful for interventional studies aimed at modifying expectations and further facilitate refinement of Janzen’s conceptual model specifically for soft tissue injuries.
As an initial step in assessing the adequacy of the model in explaining how expectations are formed for recovery of such injuries, the authors’ aimed to explore what personal and injury related factors are associated with having positive or negative expectations for whiplash associated disorders recovery. Their hypothesis was that expectations would be associated with a variety of demographic factors, factors related to the crash itself (such as post-crash pain and symptoms) and psychological factors, such as depressive symptomatology.
To the best of the authors’ knowledge, this is the first study looking at factors associated with positive recovery expectations within a whiplash associated disorders population. A variety of both modifiable and nonmodifiable variables were explored, and both variable types were found to be associated with global recovery expectation, with pain and depressive symptomatology having the greatest effect on odds ratios. The results from this analysis appear to support the notion of using a biopsychosocial approach to evaluate expectancies.
Presence of post-crash depressive symptoms and neck pain intensity (both measured simultaneously with expectations) appear to be especially important for expectations. Those with depressive symptoms are almost twice as likely to expect to get better slowly, more than twice as likely to state they do not know, and more than 4 times as likely to expect to never get better than to expect to get better quickly (the comparison group). Depressive symptomatology has previously been shown to be common following whiplash injury in those initially reporting no pre-injury mental health issues. Carroll et al. reported that 42.3% of subjects developed depressive symptoms within 6 weeks of their injury, and an additional 17.8% developed symptoms over a 1-year follow-up. In that study, those with pre-injury mental health problems were at higher risk of having a recurrent or persistent course of early onset depressive symptoms. The authors’ findings suggest that depressive symptoms are associated with recovery expectations when assessed early in the recovery process and add to the existing literature that feelings and perceptions may profoundly affect biological disease processes through behavioral and non-behavioral mechanisms.
Self reported pain intensity also shows an impact on positive recovery expectation. With respect to the 11-point NRS for neck pain intensity, every 1-unit increase in scores means individuals are at approximately 18% higher odds of expecting a slow recovery and 48% greater odds of expecting never to recover. The impact of pain on recovery is likely multi-factorial, informing behaviors required for recovery, and also mediating the resulting consequences of these behaviors. As previously mentioned, definitions of recovery differ among individuals with some reporting that pain recovery is a central tenet of recovery, and one study showing that abolition of pain appears to be paramount for reporting self-perceived recovery for a whiplash associated disorders population. The authors’ findings suggest that individual pain reports are necessary and informative as associated factors of expectations for global recovery.
Collision-related factors have generally not been associated with prognosis of whiplash associated disorders following motor vehicle collision. However, the authors’ findings show that drivers are more likely to report positive global recovery expectation compared with passengers. A modest sized association was noted for the position in vehicle variable (driver vs passenger). Although it is possible that this is a spurious finding, there may be differences between drivers and passengers that systematically influence global recovery expectations. For example, a driver is more likely to feel (or be) responsible for the collision than a passenger. Prior studies have suggested that being “at fault” for the collision is associated with somewhat faster recovery, and may also influence expectations for recovery. It is also possible that drivers and passengers differ systematically in other ways that could impact on expectations for recovery, such as unmeasured differences in health.
