Prognosis of patients with whiplash-associated disorders consulting physiotherapy: development of a predictive model for recovery
1 Institute of Environmental Medicine, Karolinska Institutet, Box 210, Stockholm, SE-17177, Sweden
2 University of Ontario, Institute of Technology, Faculty of Health Sciences, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada
3 Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Health Science Building, 155 College Street, Toronto, ON, M5T 3M7, Canada
4 Division of Health Care and Outcomes Research, Toronto Western Research Institute, University Health Network, LuCliff Place, 700 Bay Street, Suite 2201, Toronto, ON, M5G 1Z6, Canada
5 Institute of Sports Science and Clinical Biomechanics, Faculty of Health, University of Southern Denmark, Campusvej 55, Odense M, 5230, Denmark
6 School of Public Health, University of Alberta, 4075 RTF 8308-114 Street, Edmonton, AB, T6G 2E1, Canada
7 Skandinaviska Naprapathögskolan (Scandinavian College of Naprapathic Manual Medicine), Kräftriket 23A, Stockholm, SE-11419, Sweden
BMC Musculoskeletal Disorders 2012, 13:264 doi:10.1186/1471-2474-13-264Published: 29 December 2012
Patients with whiplash-associated disorders (WAD) have a generally favourable prognosis, yet some develop longstanding pain and disability. Predicting who will recover from WAD shortly after a traffic collision is very challenging for health care providers such as physical therapists. Therefore, we aimed to develop a prediction model for the recovery of WAD in a cohort of patients who consulted physical therapists within six weeks after the injury.
Our cohort included 680 adult patients with WAD who were injured in Saskatchewan, Canada, between 1997 and 1999. All patients had consulted a physical therapist as a result of the injury. Baseline prognostic factors were collected from an injury questionnaire administered by Saskatchewan Government Insurance. The outcome, global self-perceived recovery, was assessed by telephone interviews six weeks, three and six months later. Twenty-five possible baseline prognostic factors were considered in the analyses. A prediction model was built using Cox regression. The predictive ability of the model was estimated with concordance statistics (c-index). Internal validity was checked using bootstrapping.
Our final prediction model included: age, number of days to reporting the collision, neck pain intensity, low back pain intensity, pain other than neck and back pain, headache before collision and recovery expectations. The model had an acceptable level of predictive ability with a c-index of 0.68 (95% CI: 0.65, 0.71). Internal validation showed that our model was robust and had a good fit.
We developed a model predicting recovery from WAD, in a cohort of patients who consulted physical therapists. Our model has adequate predictive ability. However, to be fully incorporated in clinical practice the model needs to be validated in other populations and tested in clinical settings.