SPINE An International Journal for the study of the spine, Publish Ahead of Print DOI: 10.1097/BRS.0000000000002860 Improvement in work ability, psychological distress and pain sites in relation to low back pain prognosis: A longitudinal observational study in primary care Anne L. Nordstoga, MSc* 1 , Ottar Vasseljen, PhD 1 , Ingebrigt Meisingse, PhD 1 , Tom I. Nilsen, PhD 1,2 , Monica Unsgaard-Tøndel, PhD 1,3,4 1) Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway 2) Clinic of Anaesthesia and Intensive Care, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway 3) Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology 4) Trondheim Municipality, Department of Physiotherapy, Trondheim, Norway * Corresponding author: Anne Lovise Nordstoga Department of Public Health and Nursing Norwegian University of Science and Technology Håkon Jarls gate 11, 7030 Trondheim, Norway E-mail: anne.l.nordstoga@ntnu.no. Phone number: +47 99268260 Copyright © 2018 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.