The present study’s objective was to understand the causal mechanisms underpinning the recovery of individuals with whiplash-associated disorders (WAD). We applied Bayesian Networks (BN) to answer 2 study aims: (1) to identify the causal mechanism(s) of recovery underpinning neck-specific exercise (NSE), and (2) quantify if the cyclical pathway of the fear-avoidance model (FAM) is supported by the present data.
We analyzed a prospective cohort data set of 216 individuals with chronic WAD. Fifteen variables were used to build a BN model: treatment group (NSE with or without a behavioral approach, or general physical activity), muscle endurance, range of motion, hand strength, neck proprioception, pain catastrophizing, fear, anxiety, depression, self-efficacy, perceived work ability, disability, pain intensity, sex, and follow-up time.
The BN model showed that neck pain reduction rate was greater after NSE compared with physical activity prescription (β=0.59 points per month [P<0.001]) only in the presence of 2 mediators: global neck muscle endurance and perceived work ability. We also found the following pathway of variables that constituted the FAM: anxiety, followed by depressive symptoms, fear, catastrophizing, self-efficacy, and consequently pain.
We uncovered 2 mediators that explained the mechanisms of effect behind NSE, and proposed an alternative FAM pathway. The present study is the first to apply BN modelling to understand the causal mechanisms of recovery in WAD. In doing so, it is anticipated that such analytical methods could increase the precision of treatment of individuals with chronic WAD.
*Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham
†Department of Statistics, University of Oxford, Oxford, UK
‡Department of Medical and Health Sciences, Division of Physiotherapy, Linköping University, Linköping
§Centre for Clinical Research Sörmland, Uppsala University, Uppsala
∥Rehab Väst, County Council of Östergötland, Department of Rehabilitation and Department of Medical and Health, Sweden
ClinicalTrials.gov identifier: NCT01528579.
Supported by funding from the Swedish government through the REHSAM Foundation, the Swedish Research Council, the regional Center for Clinical Research and the County Council of Östergötland, Centre for Clinical Research Sörmland at Uppsala University, the Medical Research Council of Southeast Sweden, and the Uppsala-Örebro Regional Research Council, Sweden. The authors declare no conflict of interest.
Reprints: Bernard X.W. Liew, PhD, Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK B152TT (e-mail: firstname.lastname@example.org).
Received January 15, 2019
Received in revised form May 8, 2019
Accepted May 16, 2019