What Characterizes People Who Have an Unclear Classification Using a Treatment-Based Classification Algorithm for Low Back Pain? A Cross-Sectional Study

T.R. Stanton, BScPT, MScRS, PhD, Sansom Institute for Health Research, School of Health Sciences, University of South Australia, GPO Box 2471, Adelaide, South Australia, Australia 5001, and Neuroscience Research Australia, Sydney, New South Wales, Australia.
M.J. Hancock, BAppSc(Physio), MAppSc, PhD, Faculty of Human Sciences, Macquarie University, Sydney, New South Wales, Australia, and Faculty of Health Sciences, University of Sydney, Sydney, New South Wales, Australia.
A.T. Apeldoorn, PhD, Department of Epidemiology and Biostatistics and EMGO Institute for Health and Care Research, VU University Medical Centre, Amsterdam, the Netherlands, and Department of Rehabilitation, Medical Centre Alkmaar, Alkmaar, the Netherlands.
B.M. Wand, PT, PhD, School of Physiotherapy, University of Notre Dame Australia, Fremantle, Western Australia, Australia.
J.M. Fritz, PT, PhD, Department of Physical Therapy, College of Health, University of Utah, and Physical Therapy Division, Intermountain Healthcare, Salt Lake City, Utah.