[1] Auckland Univ Technol, Hlth & Rehabil Res Inst, Auckland 1142, New Zealand
[2] Waitemata Dist Hlth Board, Waitemata Pain Serv, Dept Anaesthesiol & Perioperat Med, Auckland 1142, New Zealand
[3] Pain Mot Int Res Grp, Brussels, Belgium
[4] Vrije Univ Brussel, Fac Phys Educ & Physiotherapy, Dept Physiotherapy Human Physiol & Anat, B-1090 Brussels, Belgium
[5] Vrije Univ Brussel, Fac Med & Pharm, Dept Publ Hlth GEWE, B-1090 Brussels, Belgium
[6] Interuniv Ctr Hlth Econ Res, I CHER, B-1090 Brussels, Belgium
[7] Univ Ziekenhuis Brussel, Dept Phys Med & Physiotherapy, B-1090 Brussels, Belgium
[8] Johns Hopkins Univ, Dept Psychiat & Behav Sci, Baltimore, MD 21287 USA