Course of recovery for whiplash associated disorders in a compensation setting

Abstract

ContextThe detailed course of recovery following compensable whiplash associated disorders (WAD) is not well understood. Some people recover within months and others report symptoms for extended periods. Recent research identified distinct recovery pathways. Identifying recovery pathways for people with this condition in compensable settings could assist clinical and claim management. Study objectiveThis study aimed to identify recovery trajectories based on disability, pain catastrophising and mental health and, secondly, to examine developmental linkages between the trajectories. Study designA cohort of 246 people with compensable WAD were followed for 24 months after a motor vehicle related injury. Outcome measuresFunctional Rating Index (FRI), Pain Catastrophising Scale (PCS) and the SF36 Mental Component Score (SF 36 MCS). MethodGroup-based trajectory analytical techniques were used to identify distinct post-injury profiles. Multinominal logistic regression modelling identified factors associated with membership of different trajectories. Results246 people were enrolled a median of 72 days after injury. Three trajectories were identified for the measures used and their prevalences, respectively, were: for disability (FRI) they were mild (47%), moderate (31%), and severe (22%); for pain catastrophising (PCS) they were non-catastrophisers (55%), moderate-low catastrophisers (32%) and clinically significant catastrophisers (13%); and, for mental health (SF36 MCS) they were good mental health (40%), moderately low mental health (42%) and severely low mental health (18%). All groups showed no further recovery beyond 12 months after injury.The significant baseline predictors of the severe disability trajectory were: lower (that means worse) bodily pain scores (SF 36 BPS) (p≤0.01); high pain catastrophising (p≤0.01); and, self-reported fair or poor general health (p=0.03).Conditional probabilities for group membership showed that the three trajectories for both PCS and FRI were linked. Dual membership was high for the mild disability and mild pain catastrophising trajectories and, for the severe disability and clinically significant pain catastrophising trajectories. ConclusionsThere is a strong and plausible association between severe disability, clinical levels of pain catastrophising and low mental health. Claimants can be identified at claim notification based on three estimated recovery trajectories. Claim and clinical interventions can be targeted to the profile within each recovery trajectory.