☆ This Research has been supported

☆ This Research has been supported by the Faculty of Health and Sport Sciences,
University of Agder, Norway.
☆☆ No conflicts of interest exist in relation to the study.
⁎ Corresponding author at: Department of Health and Nursing Sciences, University
of Agder, P.O. Box 422, NO-4604 Kristiansand, Norway. Tel.: +47 99227429.
E-mail address: anne.skisland@uia.no (A. Skisland).