of primary studies: NTNU, Norwegian Research Council, Central Norway Regional Health Authority, Helsebygg, Directorate of health, Sør- Trøndelag University College acknowledgements: Hallvard Lærum, Jan-Tore Lium, Tom Christensen, Eivind Vedvik, Berit Brattheim, Anders Grimsmo, Eric Monteiro, researchers in the Nordic e-Health research network.